GET/api/v2/spf

SPF check API

A domain's SPF record walked like a receiver walks it: the lookup bill against RFC 7208's limit of 10, void lookups, every include expanded, the senders it authorises, and with `ip` the check_host result for that address.

20 calls a minute per IP
Same engine as the SPF Record Checker tool

200 OKRecorded 2026-10-25. Send it to run the request live.

{
  "query": {
    "domain": "github.com",
    "ip": null,
    "helo": null,
    "sender": null
  },
  "verdict": "valid_no_lookups_left",
  "status": "ok",
  "result": "softfail",
  "stoppedBy": null,
  "record": "v=spf1 ip4:192.30.252.0/22 include:spf.protection.outlook.com include:_netblocks.google.com include:_netblocks2.google.com include:mail.zendesk.com include:_spf.salesforce.com include:servers.mcsv.net include:mktomail.com include:sendgrid.net ip4:62.253.227.114 ip4:166.78.69.169 ip4:166.78.69.170 ip4:166.78.71.131 ~all",
  "records": 1,
  "ttl": 300,
  "all": "~",
  "allVia": null,
  "lookups": {
    "count": 10,
    "limit": 10,
    "atLeast": false
  },
  "voidLookups": {
    "count": 1,
    "limit": 2,
    "names": [
      {
        "name": "192.0.2.1._spf.mta.salesforce.com",
        "type": "A",
        "rcode": "NXDOMAIN",
        "term": "exists:%{i}._spf.mta.salesforce.com",
        "record": "_spf.salesforce.com"
      }
    ]
  },
  "tree": [
    {
      "name": "github.com",
      "via": "root",
      "parent": null,
      "depth": 0,
      "record": "v=spf1 ip4:192.30.252.0/22 include:spf.protection.outlook.com include:_netblocks.google.com include:_netblocks2.google.com include:mail.zendesk.com include:_spf.salesforce.com include:servers.mcsv.net include:mktomail.com include:sendgrid.net ip4:62.253.227.114 ip4:166.78.69.169 ip4:166.78.69.170 ip4:166.78.71.131 ~all",
      "ttl": 300,
      "lookups": 10,
      "error": null,
      "terms": [
        {
          "term": "ip4:192.30.252.0/22",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 1024,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "include:spf.protection.outlook.com",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "include",
          "target": "spf.protection.outlook.com",
          "lookup": 1,
          "addresses": null,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "include:_netblocks.google.com",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "include",
          "target": "_netblocks.google.com",
          "lookup": 2,
          "addresses": null,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "include:_netblocks2.google.com",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "include",
          "target": "_netblocks2.google.com",
          "lookup": 3,
          "addresses": null,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "include:mail.zendesk.com",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "include",
          "target": "mail.zendesk.com",
          "lookup": 4,
          "addresses": null,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "include:_spf.salesforce.com",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "include",
          "target": "_spf.salesforce.com",
          "lookup": 5,
          "addresses": null,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "include:servers.mcsv.net",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "include",
          "target": "servers.mcsv.net",
          "lookup": 7,
          "addresses": null,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "include:mktomail.com",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "include",
          "target": "mktomail.com",
          "lookup": 8,
          "addresses": null,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "include:sendgrid.net",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "include",
          "target": "sendgrid.net",
          "lookup": 9,
          "addresses": null,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:62.253.227.114",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 1,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:166.78.69.169",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 1,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:166.78.69.170",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 1,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:166.78.71.131",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 1,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "~all",
          "kind": "mechanism",
          "qualifier": "~",
          "name": "all",
          "target": null,
          "lookup": null,
          "addresses": null,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        }
      ]
    },
    {
      "name": "spf.protection.outlook.com",
      "via": "include",
      "parent": "github.com",
      "depth": 1,
      "record": "v=spf1 ip4:40.92.0.0/15 ip4:40.107.0.0/16 ip4:52.100.0.0/15 ip4:52.102.0.0/16 ip4:52.103.0.0/17 ip4:104.47.0.0/17 ip6:2a01:111:f400::/48 ip6:2a01:111:f403::/49 ip6:2a01:111:f403:8000::/51 ip6:2a01:111:f403:c000::/51 ip6:2a01:111:f403:f000::/52 -all",
      "ttl": 232,
      "lookups": 0,
      "error": null,
      "terms": [
        {
          "term": "ip4:40.92.0.0/15",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 131072,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:40.107.0.0/16",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 65536,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:52.100.0.0/15",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 131072,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:52.102.0.0/16",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 65536,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:52.103.0.0/17",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 32768,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:104.47.0.0/17",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 32768,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip6:2a01:111:f400::/48",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip6",
          "target": null,
          "lookup": null,
          "addresses": 18446744073709552000,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip6:2a01:111:f403::/49",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip6",
          "target": null,
          "lookup": null,
          "addresses": 18446744073709552000,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip6:2a01:111:f403:8000::/51",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip6",
          "target": null,
          "lookup": null,
          "addresses": 18446744073709552000,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip6:2a01:111:f403:c000::/51",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip6",
          "target": null,
          "lookup": null,
          "addresses": 18446744073709552000,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip6:2a01:111:f403:f000::/52",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip6",
          "target": null,
          "lookup": null,
          "addresses": 18446744073709552000,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "-all",
          "kind": "mechanism",
          "qualifier": "-",
          "name": "all",
          "target": null,
          "lookup": null,
          "addresses": null,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        }
      ]
    },
    {
      "name": "_netblocks.google.com",
      "via": "include",
      "parent": "github.com",
      "depth": 1,
      "record": "v=spf1 ip4:74.125.0.0/16 ip4:209.85.128.0/17 ~all",
      "ttl": 300,
      "lookups": 0,
      "error": null,
      "terms": [
        {
          "term": "ip4:74.125.0.0/16",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 65536,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:209.85.128.0/17",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 32768,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "~all",
          "kind": "mechanism",
          "qualifier": "~",
          "name": "all",
          "target": null,
          "lookup": null,
          "addresses": null,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        }
      ]
    },
    {
      "name": "_netblocks2.google.com",
      "via": "include",
      "parent": "github.com",
      "depth": 1,
      "record": "v=spf1 ip6:2001:4860:4000::/36 ip6:2404:6800:4000::/36 ip6:2607:f8b0:4000::/36 ip6:2800:3f0:4000::/36 ip6:2a00:1450:4000::/36 ip6:2c0f:fb50:4000::/36 ~all",
      "ttl": 300,
      "lookups": 0,
      "error": null,
      "terms": [
        {
          "term": "ip6:2001:4860:4000::/36",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip6",
          "target": null,
          "lookup": null,
          "addresses": 18446744073709552000,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip6:2404:6800:4000::/36",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip6",
          "target": null,
          "lookup": null,
          "addresses": 18446744073709552000,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip6:2607:f8b0:4000::/36",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip6",
          "target": null,
          "lookup": null,
          "addresses": 18446744073709552000,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip6:2800:3f0:4000::/36",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip6",
          "target": null,
          "lookup": null,
          "addresses": 18446744073709552000,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip6:2a00:1450:4000::/36",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip6",
          "target": null,
          "lookup": null,
          "addresses": 18446744073709552000,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip6:2c0f:fb50:4000::/36",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip6",
          "target": null,
          "lookup": null,
          "addresses": 18446744073709552000,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "~all",
          "kind": "mechanism",
          "qualifier": "~",
          "name": "all",
          "target": null,
          "lookup": null,
          "addresses": null,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        }
      ]
    },
    {
      "name": "mail.zendesk.com",
      "via": "include",
      "parent": "github.com",
      "depth": 1,
      "record": "v=spf1 ip4:103.151.192.0/23 ip4:185.12.80.0/22 ip4:188.172.128.0/20 ip4:192.161.144.0/20 ip4:216.198.0.0/18 ~all",
      "ttl": 3513,
      "lookups": 0,
      "error": null,
      "terms": [
        {
          "term": "ip4:103.151.192.0/23",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 512,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:185.12.80.0/22",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 1024,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:188.172.128.0/20",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 4096,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:192.161.144.0/20",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 4096,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:216.198.0.0/18",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 16384,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "~all",
          "kind": "mechanism",
          "qualifier": "~",
          "name": "all",
          "target": null,
          "lookup": null,
          "addresses": null,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        }
      ]
    },
    {
      "name": "_spf.salesforce.com",
      "via": "include",
      "parent": "github.com",
      "depth": 1,
      "record": "v=spf1 exists:%{i}._spf.mta.salesforce.com -all",
      "ttl": 3557,
      "lookups": 1,
      "error": null,
      "terms": [
        {
          "term": "exists:%{i}._spf.mta.salesforce.com",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "exists",
          "target": "192.0.2.1._spf.mta.salesforce.com",
          "lookup": 6,
          "addresses": null,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "-all",
          "kind": "mechanism",
          "qualifier": "-",
          "name": "all",
          "target": null,
          "lookup": null,
          "addresses": null,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        }
      ]
    },
    {
      "name": "servers.mcsv.net",
      "via": "include",
      "parent": "github.com",
      "depth": 1,
      "record": "v=spf1 ip4:205.201.128.0/20 ip4:198.2.128.0/18 ip4:148.105.0.0/16 -all",
      "ttl": 595,
      "lookups": 0,
      "error": null,
      "terms": [
        {
          "term": "ip4:205.201.128.0/20",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 4096,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:198.2.128.0/18",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 16384,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:148.105.0.0/16",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 65536,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "-all",
          "kind": "mechanism",
          "qualifier": "-",
          "name": "all",
          "target": null,
          "lookup": null,
          "addresses": null,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        }
      ]
    },
    {
      "name": "mktomail.com",
      "via": "include",
      "parent": "github.com",
      "depth": 1,
      "record": "v=spf1 ip4:199.15.212.0/22 ip4:72.3.185.0/24 ip4:72.32.154.0/24 ip4:72.32.217.0/24 ip4:72.32.243.0/24 ip4:94.236.119.0/26 ip4:37.188.97.188/32 ip4:185.28.196.0/22 ip4:192.28.128.0/18 ip4:103.237.104.0/22 ip4:130.248.172.0/24 ip4:130.248.173.0/24 ~all",
      "ttl": 836,
      "lookups": 0,
      "error": null,
      "terms": [
        {
          "term": "ip4:199.15.212.0/22",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 1024,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:72.3.185.0/24",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 256,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:72.32.154.0/24",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 256,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:72.32.217.0/24",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 256,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:72.32.243.0/24",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 256,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:94.236.119.0/26",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 64,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:37.188.97.188/32",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 1,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:185.28.196.0/22",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 1024,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:192.28.128.0/18",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 16384,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:103.237.104.0/22",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 1024,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:130.248.172.0/24",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 256,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:130.248.173.0/24",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 256,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "~all",
          "kind": "mechanism",
          "qualifier": "~",
          "name": "all",
          "target": null,
          "lookup": null,
          "addresses": null,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        }
      ]
    },
    {
      "name": "sendgrid.net",
      "via": "include",
      "parent": "github.com",
      "depth": 1,
      "record": "v=spf1 ip4:167.89.0.0/17 ip4:208.117.48.0/20 ip4:50.31.32.0/19 ip4:198.37.144.0/20 ip4:198.21.0.0/21 ip4:192.254.112.0/20 ip4:168.245.0.0/17 ip4:149.72.0.0/16 ip4:159.183.0.0/16 ip4:134.128.64.0/18 ip4:159.26.176.0/20 include:ab.sendgrid.net ~all",
      "ttl": 319,
      "lookups": 1,
      "error": null,
      "terms": [
        {
          "term": "ip4:167.89.0.0/17",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 32768,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:208.117.48.0/20",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 4096,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:50.31.32.0/19",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 8192,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:198.37.144.0/20",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 4096,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:198.21.0.0/21",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 2048,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:192.254.112.0/20",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 4096,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:168.245.0.0/17",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 32768,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:149.72.0.0/16",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 65536,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:159.183.0.0/16",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 65536,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:134.128.64.0/18",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 16384,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:159.26.176.0/20",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 4096,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "include:ab.sendgrid.net",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "include",
          "target": "ab.sendgrid.net",
          "lookup": 10,
          "addresses": null,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "~all",
          "kind": "mechanism",
          "qualifier": "~",
          "name": "all",
          "target": null,
          "lookup": null,
          "addresses": null,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        }
      ]
    },
    {
      "name": "ab.sendgrid.net",
      "via": "include",
      "parent": "sendgrid.net",
      "depth": 2,
      "record": "v=spf1 ip4:223.165.113.0/24 ip4:223.165.115.0/24 ip4:223.165.118.0/23 ip4:223.165.120.0/23 ~all",
      "ttl": 1356,
      "lookups": 0,
      "error": null,
      "terms": [
        {
          "term": "ip4:223.165.113.0/24",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 256,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:223.165.115.0/24",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 256,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:223.165.118.0/23",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 512,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:223.165.120.0/23",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 512,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "~all",
          "kind": "mechanism",
          "qualifier": "~",
          "name": "all",
          "target": null,
          "lookup": null,
          "addresses": null,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        }
      ]
    }
  ],
  "senders": {
    "ipv4Ranges": 48,
    "ipv6Ranges": 11,
    "ipv4Addresses": 932421,
    "perIpTerms": 1,
    "records": [
      {
        "record": "github.com",
        "ipv4": [
          "192.30.252.0/22",
          "62.253.227.114/32",
          "166.78.69.169/32",
          "166.78.69.170/32",
          "166.78.71.131/32"
        ],
        "ipv6": [],
        "other": [],
        "perIp": []
      },
      {
        "record": "spf.protection.outlook.com",
        "ipv4": [
          "40.92.0.0/15",
          "40.107.0.0/16",
          "52.100.0.0/15",
          "52.102.0.0/16",
          "52.103.0.0/17",
          "104.47.0.0/17"
        ],
        "ipv6": [
          "2a01:111:f400::/48",
          "2a01:111:f403::/49",
          "2a01:111:f403:8000::/51",
          "2a01:111:f403:c000::/51",
          "2a01:111:f403:f000::/52"
        ],
        "other": [],
        "perIp": []
      },
      {
        "record": "_netblocks.google.com",
        "ipv4": [
          "74.125.0.0/16",
          "209.85.128.0/17"
        ],
        "ipv6": [],
        "other": [],
        "perIp": []
      },
      {
        "record": "_netblocks2.google.com",
        "ipv4": [],
        "ipv6": [
          "2001:4860:4000::/36",
          "2404:6800:4000::/36",
          "2607:f8b0:4000::/36",
          "2800:3f0:4000::/36",
          "2a00:1450:4000::/36",
          "2c0f:fb50:4000::/36"
        ],
        "other": [],
        "perIp": []
      },
      {
        "record": "mail.zendesk.com",
        "ipv4": [
          "103.151.192.0/23",
          "185.12.80.0/22",
          "188.172.128.0/20",
          "192.161.144.0/20",
          "216.198.0.0/18"
        ],
        "ipv6": [],
        "other": [],
        "perIp": []
      },
      {
        "record": "_spf.salesforce.com",
        "ipv4": [],
        "ipv6": [],
        "other": [],
        "perIp": [
          "exists:%{i}._spf.mta.salesforce.com"
        ]
      },
      {
        "record": "servers.mcsv.net",
        "ipv4": [
          "205.201.128.0/20",
          "198.2.128.0/18",
          "148.105.0.0/16"
        ],
        "ipv6": [],
        "other": [],
        "perIp": []
      },
      {
        "record": "mktomail.com",
        "ipv4": [
          "199.15.212.0/22",
          "72.3.185.0/24",
          "72.32.154.0/24",
          "72.32.217.0/24",
          "72.32.243.0/24",
          "94.236.119.0/26",
          "37.188.97.188/32",
          "185.28.196.0/22",
          "192.28.128.0/18",
          "103.237.104.0/22",
          "130.248.172.0/24",
          "130.248.173.0/24"
        ],
        "ipv6": [],
        "other": [],
        "perIp": []
      },
      {
        "record": "sendgrid.net",
        "ipv4": [
          "167.89.0.0/17",
          "208.117.48.0/20",
          "50.31.32.0/19",
          "198.37.144.0/20",
          "198.21.0.0/21",
          "192.254.112.0/20",
          "168.245.0.0/17",
          "149.72.0.0/16",
          "159.183.0.0/16",
          "134.128.64.0/18",
          "159.26.176.0/20"
        ],
        "ipv6": [],
        "other": [],
        "perIp": []
      },
      {
        "record": "ab.sendgrid.net",
        "ipv4": [
          "223.165.113.0/24",
          "223.165.115.0/24",
          "223.165.118.0/23",
          "223.165.120.0/23"
        ],
        "ipv6": [],
        "other": [],
        "perIp": []
      }
    ]
  },
  "providers": [
    {
      "term": "include:spf.protection.outlook.com",
      "target": "spf.protection.outlook.com",
      "provider": {
        "id": "microsoft-365",
        "name": "Microsoft 365"
      },
      "documented": "matches",
      "documentedInclude": "include:spf.protection.outlook.com",
      "lookups": 1
    },
    {
      "term": "include:_netblocks.google.com",
      "target": "_netblocks.google.com",
      "provider": {
        "id": "google-workspace",
        "name": "Google"
      },
      "documented": "differs",
      "documentedInclude": "include:_spf.google.com",
      "lookups": 1
    },
    {
      "term": "include:_netblocks2.google.com",
      "target": "_netblocks2.google.com",
      "provider": {
        "id": "google-workspace",
        "name": "Google"
      },
      "documented": "differs",
      "documentedInclude": "include:_spf.google.com",
      "lookups": 1
    },
    {
      "term": "include:mail.zendesk.com",
      "target": "mail.zendesk.com",
      "provider": {
        "id": "zendesk",
        "name": "Zendesk"
      },
      "documented": "matches",
      "documentedInclude": "include:mail.zendesk.com",
      "lookups": 1
    },
    {
      "term": "include:_spf.salesforce.com",
      "target": "_spf.salesforce.com",
      "provider": {
        "id": "salesforce",
        "name": "Salesforce"
      },
      "documented": "matches",
      "documentedInclude": "include:_spf.salesforce.com",
      "lookups": 2
    },
    {
      "term": "include:servers.mcsv.net",
      "target": "servers.mcsv.net",
      "provider": {
        "id": "mailchimp",
        "name": "Mailchimp"
      },
      "documented": "none",
      "documentedInclude": null,
      "lookups": 1
    },
    {
      "term": "include:mktomail.com",
      "target": "mktomail.com",
      "provider": {
        "id": "marketo",
        "name": "Marketo"
      },
      "documented": "unknown",
      "documentedInclude": null,
      "lookups": 1
    },
    {
      "term": "include:sendgrid.net",
      "target": "sendgrid.net",
      "provider": {
        "id": "sendgrid",
        "name": "Twilio SendGrid"
      },
      "documented": "matches",
      "documentedInclude": "include:sendgrid.net",
      "lookups": 2
    }
  ],
  "mailbox": {
    "provider": {
      "id": "microsoft-365",
      "name": "Microsoft 365"
    },
    "include": "include:spf.protection.outlook.com",
    "includePresent": true
  },
  "test": null,
  "issues": [
    {
      "severity": "warning",
      "code": "lookup_limit_reached",
      "message": "The record uses 10 of the 10 DNS lookups RFC 7208 allows: one more include breaks it."
    },
    {
      "severity": "info",
      "code": "void_lookup",
      "message": "1 lookup came back empty (192.0.2.1._spf.mta.salesforce.com): allowed up to 2."
    },
    {
      "severity": "info",
      "code": "per_ip_terms",
      "message": "exists:%{i}._spf.mta.salesforce.com in _spf.salesforce.com is decided per sending IP (a macro or exists:), so the senders it allows can't be listed."
    },
    {
      "severity": "info",
      "code": "large_txt_answer",
      "message": "The TXT records at the name come to 1586 bytes, over the 450 RFC 7208 §3.4 suggests for a 512-byte UDP answer; resolvers fall back to TCP, so it rarely matters."
    }
  ],
  "tookMs": 281
}

Jump to a section

How it works

Reads the TXT records at the name and walks the SPF record the way a receiving mail server does: grammar first, then every term in order with the running count of DNS lookups (include, a, mx, ptr, exists, redirect) against the limit of 10 and void lookups against 2. Unlike a receiver it keeps counting past the 11th, so a broken record shows its whole bill. tree holds every record it reached; senders the ranges they authorise; providers the companies behind the includes beside what they document.

Without ip the record is walked for 192.0.2.1, an address nobody lists, so every term runs and result is what the record does with forged mail. With ip (and optionally helo and sender), test is RFC 7208 check_host for that address: pass, fail, softfail, neutral, none, permerror or temperror, and the path of terms that decided.

DNS is Google Public DNS with Cloudflare's 1.1.1.1 as a second opinion; the TTL comes from the domain's own nameserver. A failed lookup is temperror ("couldn't check", incomplete), never "broken", and a permerror is never reported as fail. Agrees with pyspf, the RFC's reference implementation, on 25 of 25 test domains.

Query parameters

domainstringrequired
The domain whose SPF record to check. It is checked exactly as given: SPF has no inheritance, so mail.example.com has a record of its own. A URL (its host), an email address (its domain), an IDN in Unicode or a trailing dot are read the way the tool page reads them; the normalised name comes back in query.domain.
ipstringoptional
An IPv4 or IPv6 sending address to test with RFC 7208 check_host; the answer's test says what receivers decide for it and which term matched.
helostringoptional
With ip: the HELO/EHLO host name the server announces (macros like %{h} expand with it); its own SPF record is checked too (test.heloResult).
senderstringoptional
With ip: the MAIL FROM address or domain (default postmaster@domain); macros like %{l} and %{s} expand with it.

Response fields

200 with this JSON object, plus tookMs, and incomplete with warnings when a source failed. Fields marked optional appear only when they apply.

queryobjectalways
What was looked up, normalised (lower case, no trailing dot, IDNs as Punycode).
Show 4 fields
- domainstringalways
  The domain checked, lower case, IDNs as Punycode.
- ipstring or nullalways
  The address tested with check_host (an IPv4-mapped IPv6 address becomes its IPv4); null without ip.
- helostring or nullalways
  The HELO name given, normalised; null when none.
- senderstring or nullalways
  The MAIL FROM given, normalised to local@domain; null when none (check_host then uses postmaster@<domain>).
verdictstring or nullalways
The record's health for receivers: valid, valid_no_lookups_left (10 of 10), valid_redirect (hands every check to another record), valid_uses_ptr; allows_everyone (+all, or an include ending in +all), no_record, near_miss (a TXT meant as SPF that receivers ignore), multiple_records, syntax_error, too_many_lookups, too_many_void_lookups, include_without_spf, redirect_without_spf, include_loop, mx_too_many_hosts; dns_error and check_incomplete mean we couldn't check it all. null only when the walk didn't run.
one of "valid", "valid_no_lookups_left", "valid_redirect", "valid_uses_ptr", "allows_everyone", "no_record", "near_miss", "multiple_records", "syntax_error", "too_many_lookups", "too_many_void_lookups", "include_without_spf", "redirect_without_spf", "include_loop", "mx_too_many_hosts", "dns_error", "check_incomplete", null
statusstringalways
The verdict in one word: ok, warning, error (receivers fail it or it lets everyone pass), unknown (couldn't check).
one of "ok", "warning", "error", "unknown"
resultstring or nullalways
RFC 7208 check_host's result for a sender the record doesn't list (192.0.2.1, an address nobody lists): what the record does with forged mail. pass here means every server passes.
one of "pass", "fail", "softfail", "neutral", "none", "permerror", "temperror", null
stoppedBystring or nullalways
Why result is permerror or temperror: the 11th lookup, the 3rd void lookup, an include or redirect without SPF, a syntax error, two records, a DNS failure, an mx with more than 10 hosts, a loop, nesting, our cap or our deadline. null otherwise.
one of "lookups", "voids", "include_nospf", "redirect_nospf", "syntax", "multiple", "temperror", "mx10", "loop", "deep", "cap", "timeout", null
recordstring or nullalways
The domain's SPF record as published (the first, when there are several); null when there is none.
recordsintegeralways
TXT records at the name that start with v=spf1. Two or more is a permerror.
ttlinteger or nullalways
The record's TTL in seconds, asked of the domain's own nameserver (the resolver's remaining TTL when that fails).
allstring or nullalways
The all ending unlisted senders get, through a redirect when allVia names one; null when the record has none (they get neutral).
one of "+", "-", "~", "?", null
allViastring or nullalways
The redirect target whose all applies; null when the record's own all (or none) applies.
lookupsobjectalways
DNS lookups the record needs, counted like a receiver (include, a, mx, ptr, exists, redirect: 1 each).
- countintegeralways
  Lookups needed for a sender the record doesn't list. Counted past the 10th so a broken record shows its whole bill ("18 needed").
- limitintegeralways
  RFC 7208's limit: 10. Receivers stop at the 11th with permerror.
- atLeastbooleanalways
  true when the count stopped at 50: the record needs at least that many.
voidLookupsobjectalways
Lookups that came back empty (NXDOMAIN or no records): more than 2 is permerror.
- countintegeralways
  Void lookups a receiver counts.
- limitintegeralways
  RFC 7208's limit: 2.
- namesarray of objectsalways
  Each void lookup, in the order a receiver meets it.
  Show 5 fields
  - namestringalways
    The name asked.
  - typestringalways
    The record type asked.
    one of "A", "AAAA", "MX", "PTR"
  - rcodestringalways
    The answer's code: NXDOMAIN, or NOERROR with no records.
  - termstringalways
    The term that asked.
  - recordstringalways
    The record holding that term.
treearray of objectsalways
The whole record tree, flattened depth first in the order a receiver reads it: the domain's record, then each include's (rebuild the tree with parent). Empty when there is no record. At most 60 records.
Show 9 fields
- namestringalways
  The name the record was read at.
- viastringalways
  How the walk reached it: the checked domain itself, an include: or a redirect=.
  one of "root", "include", "redirect"
- parentstring or nullalways
  The record that includes or redirects to this one; null for the root.
- depthintegeralways
  Nesting depth: 0 for the domain's own record.
- recordstring or nullalways
  The SPF record's text as published (TXT strings joined); null when there is none.
- ttlinteger or nullalways
  The record's TTL in seconds, as the resolver returned it.
- lookupsintegeralways
  DNS lookups spent inside this record and everything it reaches (the include term itself not counted).
- errorstring or nullalways
  Why the walk couldn't use this record: dns_error (the lookup failed), no_record (no v=spf1 at the name), multiple_records, syntax_error, too_deep (nesting) or too_large (our own cap).
  one of "dns_error", "no_record", "multiple_records", "syntax_error", "too_deep", "too_large", null
- termsarray of objectsalways
  The record's terms in order (at most 120).
  Show 11 fields
  - termstringalways
    The term as written, e.g. include:_spf.google.com or ~all.
  - kindstringalways
    mechanism (all, include, a, mx, ptr, ip4, ip6, exists), modifier (redirect=, exp= or an unknown one) or invalid (breaks RFC 7208's grammar).
    one of "mechanism", "modifier", "invalid"
  - qualifierstring or nullalways
    A mechanism's qualifier: + pass (the default), - fail, ~ softfail, ? neutral. null for modifiers and invalid terms.
    one of "+", "-", "~", "?", null
  - namestring or nullalways
    The mechanism or modifier name in lower case (include, ip4, redirect…); null for an invalid term.
  - targetstring or nullalways
    The domain the term asks about (include, redirect, a, mx, exists, ptr), macros expanded for 192.0.2.1; null for ip4/ip6/all.
  - lookupinteger or nullalways
    The running count of DNS lookups after this term, when it costs one (include, a, mx, ptr, exists, redirect); null otherwise. Over 10 is permerror.
  - addressesinteger or nullalways
    ip4/ip6: how many addresses the range holds (IPv6 capped at 2^64); null for other terms.
  - ipsarray of strings or nullalways
    a and mx: the addresses the term resolved to (at most 32); null for other terms.
  - hostsarray of strings or nullalways
    mx: the mail server names; ptr: the validated reverse names; null for other terms.
  - evaluatedbooleanalways
    false when a receiver never reaches the term: it comes after all, or after the check already stopped (the 11th lookup, the 3rd void).
  - problemstring or nullalways
    What is wrong with this term, if anything: a grammar fault, an unknown modifier, a term after all, a redirect ignored because of all, an include loop, an include of a name with no SPF record, or a DNS failure. Details are in issues.
    one of "syntax_error", "unknown_modifier", "after_all", "redirect_ignored", "loop", "no_spf_record", "dns_error", null
sendersobject or nullalways
Who the record authorises, for a sender it doesn't list (every term a receiver reaches): ip4/ip6 ranges and the addresses behind a/mx terms, per record. null when there is no record.
Show 5 fields
- ipv4Rangesintegeralways
  IPv4 ranges that pass, across the tree.
- ipv6Rangesintegeralways
  IPv6 ranges that pass, across the tree.
- ipv4Addressesintegeralways
  IPv4 addresses those ranges hold, summed (ranges may overlap: an upper bound).
- perIpTermsintegeralways
  Terms decided per sending IP (exists:, ptr, macros) whose senders can't be listed.
- recordsarray of objectsalways
  Per record of the tree that lists senders: the domain's own first, then each include's.
  Show 5 fields
  - recordstringalways
    The record's name.
  - ipv4array of stringsalways
    IPv4 ranges (CIDR) that pass; a/mx addresses as /32 (or the term's prefix).
  - ipv6array of stringsalways
    IPv6 ranges (CIDR) that pass.
  - otherarray of objectsalways
    Ranges listed with another qualifier: - (denied), ~ (softfail) or ? (neutral). They don't authorise.
    Show 2 fields
    rangestringalways
    The CIDR range.
    qualifierstringalways
    Its qualifier.
    one of "-", "~", "?"
  - perIparray of stringsalways
    Terms in this record decided per sending IP (exists:, ptr, macros), as written.
providersarray of objectsalways
Each top-level include or redirect, with the company behind it and what that company documents. The domain's own names are left out.
Show 6 fields
- termstringalways
  The term as written.
- targetstringalways
  The name it includes.
- providerobject or nullalways
  The company behind the include (from our list of 70+ senders' documented includes); null when we don't know it.
  Show 2 fields
  - idstringalways
    Our stable id for the company, e.g. google, microsoft365, sendgrid.
  - namestringalways
    Its name as it writes it, e.g. Google Workspace.
- documentedstringalways
  Against the provider's documentation: matches the documented include, differs (it documents documentedInclude), none (it documents no SPF include), unknown (not in our list).
  one of "matches", "differs", "none", "unknown"
- documentedIncludestring or nullalways
  The include the provider documents, when it differs or matches; null otherwise.
- lookupsintegeralways
  DNS lookups this include costs here (itself plus everything it reaches).
mailboxobject or nullalways
The mailbox provider the domain's MX names (security gateways skipped), and whether the record carries its documented include anywhere in the tree. null when the MX names no provider we know.
- providerobjectalways
  The mailbox provider.
  Show 2 fields
  - idstringalways
    Our stable id for the company, e.g. google, microsoft365, sendgrid.
  - namestringalways
    Its name as it writes it, e.g. Google Workspace.
- includestring or nullalways
  The include it documents; null when it documents none.
- includePresentbooleanalways
  The record (or one of its includes) carries that include.
testobject or nullalways
With ip: RFC 7208 check_host for that address, as a receiver runs it. null without ip.
Show 8 fields
- ipstringalways
  The address tested.
- helostring or nullalways
  The HELO name used; null when none was given.
- senderstringalways
  The MAIL FROM used (postmaster@<domain> when none was given).
- resultstringalways
  check_host's result: pass (authorised), fail (-), softfail (~), neutral (?), none (no record), permerror (the record is broken), temperror (a DNS lookup failed).
  one of "pass", "fail", "softfail", "neutral", "none", "permerror", "temperror"
- stoppedBystring or nullalways
  Why the result is permerror or temperror; null otherwise.
  one of "lookups", "voids", "include_nospf", "redirect_nospf", "syntax", "multiple", "temperror", "mx10", "loop", "deep", "cap", "timeout", null
- patharray of objectsalways
  The terms that decided, from the domain's record down through includes to the term that matched (the last). Empty when no term matched (the default neutral, or none).
  Show 2 fields
  - termstringalways
    The term.
  - recordstringalways
    The record holding it.
- lookupsintegeralways
  DNS lookups this check spent.
- heloResultobject or nullalways
  With helo: check_host of the HELO name's own SPF record for the same address.
  Show 2 fields
  - namestringalways
    The HELO name.
  - resultstringalways
    Its result.
    one of "pass", "fail", "softfail", "neutral", "none", "permerror", "temperror"
issuesarray of objectsalways
Problems in the record, worst first: the SPF Record Checker's readings (RFC 7208). error breaks something (receivers fail it), warning risks it, info is worth knowing.
- severitystringalways
  error breaks something, warning risks it, info is worth knowing.
  one of "error", "warning", "info"
- codestringalways
  Stable machine-readable code.
- messagestringalways
  The problem and what to do about it, in plain English.

Errors

400 missing_parameter helo or sender is given without ip.
429 rate_limited The domain (its registrable domain) was checked 30 times in the last minute by all callers together, or every caller together reached 600 a minute: retry after Retry-After seconds.

Plus the errors every endpoint can return: 400 for a missing or unreadable parameter, 429 past the limit, 503 when every source failed.

curl "https://dnsrobot.net/api/v2/spf?domain=github.com"

const params = new URLSearchParams({ domain: "github.com" });
const res = await fetch(`https://dnsrobot.net/api/v2/spf?${params}`);
const data = await res.json();
if (!res.ok) throw new Error(data.error.message);
console.log(data.verdict);

import requests

r = requests.get(
    "https://dnsrobot.net/api/v2/spf",
    params={"domain": "github.com"},
    timeout=30,
)
data = r.json()
if not r.ok:
    raise RuntimeError(data["error"]["message"])
print(data["verdict"])

package main

import (
	"encoding/json"
	"fmt"
	"net/http"
	"net/url"
)

func main() {
	q := url.Values{"domain": {"github.com"}}
	res, err := http.Get("https://dnsrobot.net/api/v2/spf?" + q.Encode())
	if err != nil {
		panic(err)
	}
	defer res.Body.Close()
	var data map[string]any
	if err := json.NewDecoder(res.Body).Decode(&data); err != nil {
		panic(err)
	}
	if res.StatusCode != http.StatusOK {
		panic(data["error"])
	}
	fmt.Println(data["verdict"])
}

<?php
$query = http_build_query(["domain" => "github.com"]);
$context = stream_context_create(["http" => ["ignore_errors" => true, "timeout" => 30]]);
$data = json_decode(file_get_contents("https://dnsrobot.net/api/v2/spf?" . $query, false, $context), true);
if (isset($data["error"])) {
    throw new RuntimeException($data["error"]["message"]);
}
print_r($data["verdict"]);

require "net/http"
require "json"

uri = URI("https://dnsrobot.net/api/v2/spf")
uri.query = URI.encode_www_form(domain: "github.com")
data = JSON.parse(Net::HTTP.get(uri))
raise data["error"]["message"] if data["error"]
puts data["verdict"]

// Cargo.toml: reqwest = { version = "0.13", features = ["blocking", "json"] }, serde_json = "1"
fn main() -> Result<(), Box<dyn std::error::Error>> {
    let res = reqwest::blocking::get("https://dnsrobot.net/api/v2/spf?domain=github.com")?;
    let ok = res.status().is_success();
    let data: serde_json::Value = res.json()?;
    if !ok {
        return Err(data["error"]["message"].to_string().into());
    }
    println!("{}", data["verdict"]);
    Ok(())
}

using System.Text.Json;

using var http = new HttpClient();
var res = await http.GetAsync("https://dnsrobot.net/api/v2/spf?domain=github.com");
var data = JsonDocument.Parse(await res.Content.ReadAsStringAsync()).RootElement;
if (!res.IsSuccessStatusCode)
    throw new Exception(data.GetProperty("error").GetProperty("message").GetString());
Console.WriteLine(data.GetProperty("verdict"));

github.com's record

GET /api/v2/spf?domain=github.com

200 OKRecorded 2026-10-25

{
  "query": {
    "domain": "github.com",
    "ip": null,
    "helo": null,
    "sender": null
  },
  "verdict": "valid_no_lookups_left",
  "status": "ok",
  "result": "softfail",
  "stoppedBy": null,
  "record": "v=spf1 ip4:192.30.252.0/22 include:spf.protection.outlook.com include:_netblocks.google.com incl…",
  "records": 1,
  "ttl": 300,
  "all": "~",
  "allVia": null,
  "lookups": {
    "count": 10,
    "limit": 10,
    "atLeast": false
  },
  "voidLookups": {
    "count": 1,
    "limit": 2,
    "names": [
      {
        "name": "192.0.2.1._spf.mta.salesforce.com",
        "type": "A",
        "rcode": "NXDOMAIN",
        "term": "exists:%{i}._spf.mta.salesforce.com",
        "record": "_spf.salesforce.com"
      }
    ]
  },
  "tree": [
    {
      "name": "github.com",
      "via": "root",
      "parent": null,
      "depth": 0,
      "record": "v=spf1 ip4:192.30.252.0/22 include:spf.protection.outlook.com include:_netblocks.google.com incl…",
      "ttl": 300,
      "lookups": 10,
      "error": null,
      "terms": [
        {
          "term": "ip4:192.30.252.0/22",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 1024,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "include:spf.protection.outlook.com",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "include",
          "target": "spf.protection.outlook.com",
          "lookup": 1,
          "addresses": null,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "include:_netblocks.google.com",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "include",
          "target": "_netblocks.google.com",
          "lookup": 2,
          "addresses": null,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        // … 11 more items
      ]
    },
    {
      "name": "spf.protection.outlook.com",
      "via": "include",
      "parent": "github.com",
      "depth": 1,
      "record": "v=spf1 ip4:40.92.0.0/15 ip4:40.107.0.0/16 ip4:52.100.0.0/15 ip4:52.102.0.0/16 ip4:52.103.0.0/17 …",
      "ttl": 232,
      "lookups": 0,
      "error": null,
      "terms": [
        {
          "term": "ip4:40.92.0.0/15",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 131072,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:40.107.0.0/16",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 65536,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:52.100.0.0/15",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 131072,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        // … 9 more items
      ]
    },
    {
      "name": "_netblocks.google.com",
      "via": "include",
      "parent": "github.com",
      "depth": 1,
      "record": "v=spf1 ip4:74.125.0.0/16 ip4:209.85.128.0/17 ~all",
      "ttl": 300,
      "lookups": 0,
      "error": null,
      "terms": [
        {
          "term": "ip4:74.125.0.0/16",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 65536,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:209.85.128.0/17",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 32768,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "~all",
          "kind": "mechanism",
          "qualifier": "~",
          "name": "all",
          "target": null,
          "lookup": null,
          "addresses": null,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        }
      ]
    },
    // … 7 more items
  ],
  "senders": {
    "ipv4Ranges": 48,
    "ipv6Ranges": 11,
    "ipv4Addresses": 932421,
    "perIpTerms": 1,
    "records": [
      {
        "record": "github.com",
        "ipv4": [
          "192.30.252.0/22",
          "62.253.227.114/32",
          "166.78.69.169/32",
          // … 2 more items
        ],
        "ipv6": [],
        "other": [],
        "perIp": []
      },
      {
        "record": "spf.protection.outlook.com",
        "ipv4": [
          "40.92.0.0/15",
          "40.107.0.0/16",
          "52.100.0.0/15",
          // … 3 more items
        ],
        "ipv6": [
          "2a01:111:f400::/48",
          "2a01:111:f403::/49",
          "2a01:111:f403:8000::/51",
          // … 2 more items
        ],
        "other": [],
        "perIp": []
      },
      {
        "record": "_netblocks.google.com",
        "ipv4": [
          "74.125.0.0/16",
          "209.85.128.0/17"
        ],
        "ipv6": [],
        "other": [],
        "perIp": []
      },
      // … 7 more items
    ]
  },
  "providers": [
    {
      "term": "include:spf.protection.outlook.com",
      "target": "spf.protection.outlook.com",
      "provider": {
        "id": "microsoft-365",
        "name": "Microsoft 365"
      },
      "documented": "matches",
      "documentedInclude": "include:spf.protection.outlook.com",
      "lookups": 1
    },
    {
      "term": "include:_netblocks.google.com",
      "target": "_netblocks.google.com",
      "provider": {
        "id": "google-workspace",
        "name": "Google"
      },
      "documented": "differs",
      "documentedInclude": "include:_spf.google.com",
      "lookups": 1
    },
    {
      "term": "include:_netblocks2.google.com",
      "target": "_netblocks2.google.com",
      "provider": {
        "id": "google-workspace",
        "name": "Google"
      },
      "documented": "differs",
      "documentedInclude": "include:_spf.google.com",
      "lookups": 1
    },
    // … 5 more items
  ],
  "mailbox": {
    "provider": {
      "id": "microsoft-365",
      "name": "Microsoft 365"
    },
    "include": "include:spf.protection.outlook.com",
    "includePresent": true
  },
  "test": null,
  "issues": [
    {
      "severity": "warning",
      "code": "lookup_limit_reached",
      "message": "The record uses 10 of the 10 DNS lookups RFC 7208 allows: one more include breaks it."
    },
    {
      "severity": "info",
      "code": "void_lookup",
      "message": "1 lookup came back empty (192.0.2.1._spf.mta.salesforce.com): allowed up to 2."
    },
    {
      "severity": "info",
      "code": "per_ip_terms",
      "message": "exists:%{i}._spf.mta.salesforce.com in _spf.salesforce.com is decided per sending IP (a macro or…"
    },
    // … 1 more item
  ],
  "tookMs": 281
}

Shortened for the page: long lists show their first items.

Is 192.30.252.1 allowed to send for github.com?

GET /api/v2/spf?domain=github.com&ip=192.30.252.1

200 OKRecorded 2026-10-25

{
  "query": {
    "domain": "github.com",
    "ip": "192.30.252.1",
    "helo": null,
    "sender": null
  },
  "verdict": "valid_no_lookups_left",
  "status": "ok",
  "result": "softfail",
  "stoppedBy": null,
  "record": "v=spf1 ip4:192.30.252.0/22 include:spf.protection.outlook.com include:_netblocks.google.com incl…",
  "records": 1,
  "ttl": 300,
  "all": "~",
  "allVia": null,
  "lookups": {
    "count": 10,
    "limit": 10,
    "atLeast": false
  },
  "voidLookups": {
    "count": 1,
    "limit": 2,
    "names": [
      {
        "name": "192.0.2.1._spf.mta.salesforce.com",
        "type": "A",
        "rcode": "NXDOMAIN",
        "term": "exists:%{i}._spf.mta.salesforce.com",
        "record": "_spf.salesforce.com"
      }
    ]
  },
  "tree": [
    {
      "name": "github.com",
      "via": "root",
      "parent": null,
      "depth": 0,
      "record": "v=spf1 ip4:192.30.252.0/22 include:spf.protection.outlook.com include:_netblocks.google.com incl…",
      "ttl": 300,
      "lookups": 10,
      "error": null,
      "terms": [
        {
          "term": "ip4:192.30.252.0/22",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 1024,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "include:spf.protection.outlook.com",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "include",
          "target": "spf.protection.outlook.com",
          "lookup": 1,
          "addresses": null,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "include:_netblocks.google.com",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "include",
          "target": "_netblocks.google.com",
          "lookup": 2,
          "addresses": null,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        // … 11 more items
      ]
    },
    {
      "name": "spf.protection.outlook.com",
      "via": "include",
      "parent": "github.com",
      "depth": 1,
      "record": "v=spf1 ip4:40.92.0.0/15 ip4:40.107.0.0/16 ip4:52.100.0.0/15 ip4:52.102.0.0/16 ip4:52.103.0.0/17 …",
      "ttl": 482,
      "lookups": 0,
      "error": null,
      "terms": [
        {
          "term": "ip4:40.92.0.0/15",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 131072,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:40.107.0.0/16",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 65536,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:52.100.0.0/15",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 131072,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        // … 9 more items
      ]
    },
    {
      "name": "_netblocks.google.com",
      "via": "include",
      "parent": "github.com",
      "depth": 1,
      "record": "v=spf1 ip4:74.125.0.0/16 ip4:209.85.128.0/17 ~all",
      "ttl": 300,
      "lookups": 0,
      "error": null,
      "terms": [
        {
          "term": "ip4:74.125.0.0/16",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 65536,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:209.85.128.0/17",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 32768,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "~all",
          "kind": "mechanism",
          "qualifier": "~",
          "name": "all",
          "target": null,
          "lookup": null,
          "addresses": null,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        }
      ]
    },
    // … 7 more items
  ],
  "senders": {
    "ipv4Ranges": 48,
    "ipv6Ranges": 11,
    "ipv4Addresses": 932421,
    "perIpTerms": 1,
    "records": [
      {
        "record": "github.com",
        "ipv4": [
          "192.30.252.0/22",
          "62.253.227.114/32",
          "166.78.69.169/32",
          // … 2 more items
        ],
        "ipv6": [],
        "other": [],
        "perIp": []
      },
      {
        "record": "spf.protection.outlook.com",
        "ipv4": [
          "40.92.0.0/15",
          "40.107.0.0/16",
          "52.100.0.0/15",
          // … 3 more items
        ],
        "ipv6": [
          "2a01:111:f400::/48",
          "2a01:111:f403::/49",
          "2a01:111:f403:8000::/51",
          // … 2 more items
        ],
        "other": [],
        "perIp": []
      },
      {
        "record": "_netblocks.google.com",
        "ipv4": [
          "74.125.0.0/16",
          "209.85.128.0/17"
        ],
        "ipv6": [],
        "other": [],
        "perIp": []
      },
      // … 7 more items
    ]
  },
  "providers": [
    {
      "term": "include:spf.protection.outlook.com",
      "target": "spf.protection.outlook.com",
      "provider": {
        "id": "microsoft-365",
        "name": "Microsoft 365"
      },
      "documented": "matches",
      "documentedInclude": "include:spf.protection.outlook.com",
      "lookups": 1
    },
    {
      "term": "include:_netblocks.google.com",
      "target": "_netblocks.google.com",
      "provider": {
        "id": "google-workspace",
        "name": "Google"
      },
      "documented": "differs",
      "documentedInclude": "include:_spf.google.com",
      "lookups": 1
    },
    {
      "term": "include:_netblocks2.google.com",
      "target": "_netblocks2.google.com",
      "provider": {
        "id": "google-workspace",
        "name": "Google"
      },
      "documented": "differs",
      "documentedInclude": "include:_spf.google.com",
      "lookups": 1
    },
    // … 5 more items
  ],
  "mailbox": {
    "provider": {
      "id": "microsoft-365",
      "name": "Microsoft 365"
    },
    "include": "include:spf.protection.outlook.com",
    "includePresent": true
  },
  "test": {
    "ip": "192.30.252.1",
    "helo": null,
    "sender": "postmaster@github.com",
    "result": "pass",
    "stoppedBy": null,
    "path": [
      {
        "term": "ip4:192.30.252.0/22",
        "record": "github.com"
      }
    ],
    "lookups": 0,
    "heloResult": null
  },
  "issues": [
    {
      "severity": "warning",
      "code": "lookup_limit_reached",
      "message": "The record uses 10 of the 10 DNS lookups RFC 7208 allows: one more include breaks it."
    },
    {
      "severity": "info",
      "code": "void_lookup",
      "message": "1 lookup came back empty (192.0.2.1._spf.mta.salesforce.com): allowed up to 2."
    },
    {
      "severity": "info",
      "code": "per_ip_terms",
      "message": "exists:%{i}._spf.mta.salesforce.com in _spf.salesforce.com is decided per sending IP (a macro or…"
    },
    // … 1 more item
  ],
  "tookMs": 236
}

Shortened for the page: long lists show their first items.

cloudflare.com's record

GET /api/v2/spf?domain=cloudflare.com

200 OKRecorded 2026-10-25

{
  "query": {
    "domain": "cloudflare.com",
    "ip": null,
    "helo": null,
    "sender": null
  },
  "verdict": "valid",
  "status": "ok",
  "result": "fail",
  "stoppedBy": null,
  "record": "v=spf1 ip4:199.15.212.0/22 ip4:173.245.48.0/20 include:_spf.google.com include:spf1.mcsv.net inc…",
  "records": 1,
  "ttl": 300,
  "all": "-",
  "allVia": null,
  "lookups": {
    "count": 7,
    "limit": 10,
    "atLeast": false
  },
  "voidLookups": {
    "count": 1,
    "limit": 2,
    "names": [
      {
        "name": "192.0.2.1._spf.mta.salesforce.com",
        "type": "A",
        "rcode": "NXDOMAIN",
        "term": "exists:%{i}._spf.mta.salesforce.com",
        "record": "_spf.salesforce.com"
      }
    ]
  },
  "tree": [
    {
      "name": "cloudflare.com",
      "via": "root",
      "parent": null,
      "depth": 0,
      "record": "v=spf1 ip4:199.15.212.0/22 ip4:173.245.48.0/20 include:_spf.google.com include:spf1.mcsv.net inc…",
      "ttl": 300,
      "lookups": 7,
      "error": null,
      "terms": [
        {
          "term": "ip4:199.15.212.0/22",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 1024,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:173.245.48.0/20",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 4096,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "include:_spf.google.com",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "include",
          "target": "_spf.google.com",
          "lookup": 1,
          "addresses": null,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        // … 6 more items
      ]
    },
    {
      "name": "_spf.google.com",
      "via": "include",
      "parent": "cloudflare.com",
      "depth": 1,
      "record": "v=spf1 ip4:74.125.0.0/16 ip4:209.85.128.0/17 ip6:2001:4860:4864::/56 ip6:2404:6800:4864::/56 ip6…",
      "ttl": 300,
      "lookups": 0,
      "error": null,
      "terms": [
        {
          "term": "ip4:74.125.0.0/16",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 65536,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:209.85.128.0/17",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 32768,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip6:2001:4860:4864::/56",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip6",
          "target": null,
          "lookup": null,
          "addresses": 18446744073709552000,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        // … 6 more items
      ]
    },
    {
      "name": "spf1.mcsv.net",
      "via": "include",
      "parent": "cloudflare.com",
      "depth": 1,
      "record": "v=spf1 ip4:205.201.128.0/20 ip4:198.2.128.0/18 ?all",
      "ttl": 20808,
      "lookups": 0,
      "error": null,
      "terms": [
        {
          "term": "ip4:205.201.128.0/20",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 4096,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "ip4:198.2.128.0/18",
          "kind": "mechanism",
          "qualifier": "+",
          "name": "ip4",
          "target": null,
          "lookup": null,
          "addresses": 16384,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        },
        {
          "term": "?all",
          "kind": "mechanism",
          "qualifier": "?",
          "name": "all",
          "target": null,
          "lookup": null,
          "addresses": null,
          "ips": null,
          "hosts": null,
          "evaluated": true,
          "problem": null
        }
      ]
    },
    // … 4 more items
  ],
  "senders": {
    "ipv4Ranges": 53,
    "ipv6Ranges": 6,
    "ipv4Addresses": 154782,
    "perIpTerms": 1,
    "records": [
      {
        "record": "cloudflare.com",
        "ipv4": [
          "199.15.212.0/22",
          "173.245.48.0/20"
        ],
        "ipv6": [],
        "other": [],
        "perIp": []
      },
      {
        "record": "_spf.google.com",
        "ipv4": [
          "74.125.0.0/16",
          "209.85.128.0/17"
        ],
        "ipv6": [
          "2001:4860:4864::/56",
          "2404:6800:4864::/56",
          "2607:f8b0:4864::/56",
          // … 3 more items
        ],
        "other": [],
        "perIp": []
      },
      {
        "record": "spf1.mcsv.net",
        "ipv4": [
          "205.201.128.0/20",
          "198.2.128.0/18"
        ],
        "ipv6": [],
        "other": [],
        "perIp": []
      },
      // … 4 more items
    ]
  },
  "providers": [
    {
      "term": "include:_spf.google.com",
      "target": "_spf.google.com",
      "provider": {
        "id": "google-workspace",
        "name": "Google Workspace"
      },
      "documented": "matches",
      "documentedInclude": "include:_spf.google.com",
      "lookups": 1
    },
    {
      "term": "include:spf1.mcsv.net",
      "target": "spf1.mcsv.net",
      "provider": {
        "id": "mailchimp",
        "name": "Mailchimp"
      },
      "documented": "none",
      "documentedInclude": null,
      "lookups": 1
    },
    {
      "term": "include:spf.mandrillapp.com",
      "target": "spf.mandrillapp.com",
      "provider": {
        "id": "mandrill",
        "name": "Mandrill"
      },
      "documented": "unknown",
      "documentedInclude": null,
      "lookups": 1
    },
    // … 3 more items
  ],
  "mailbox": null,
  "test": null,
  "issues": [
    {
      "severity": "info",
      "code": "void_lookup",
      "message": "1 lookup came back empty (192.0.2.1._spf.mta.salesforce.com): allowed up to 2."
    },
    {
      "severity": "info",
      "code": "per_ip_terms",
      "message": "exists:%{i}._spf.mta.salesforce.com in _spf.salesforce.com is decided per sending IP (a macro or…"
    },
    {
      "severity": "info",
      "code": "large_txt_answer",
      "message": "The TXT records at the name come to 2133 bytes, over the 450 RFC 7208 §3.4 suggests for a 512-by…"
    }
  ],
  "tookMs": 399
}

Shortened for the page: long lists show their first items.

SPF check API

How it works

Query parameters

Response fields

Errors

Code samples