Free deliverability tool
SPF record checker
SPF authorises which servers may send for your domain. It permits a maximum of ten DNS lookups, includes nest, and exceeding the limit is a permerror that most receivers treat as a failure — which is why adding a fourth vendor silently breaks the three that were working.
Worked example — example.com
Sample demonstration- PassRecord found
v=spf1 include:sadasend.net include:_spf.google.com ~all - PassRecord count
1Two SPF records is a permerror. One is correct.
- CheckDNS lookups
6 of 10Four remaining. Each new vendor typically costs 1–3.
- CheckAll mechanism
~all (softfail)Move to -all once you are confident every sender is listed.
Valid, with headroom for roughly two more vendors before you hit the lookup limit.
SadaSend runs these checks continuously on your sending domains, and refuses to send until they pass — so mail Gmail would reject never leaves.
Start freeWhat this checks
- The record exists and there is exactly one
- Syntax is valid and the mechanisms parse
- Every include is resolved and counted against the ten-lookup limit
- The all mechanism is present and its qualifier is sensible
Questions
Other tools
- DKIM validatorFetch a DKIM public key by selector, check the key length, and verify the record parses.
- DMARC checkerParse a DMARC record and explain what it actually does to mail that fails authentication.
- MX lookupResolve a domain's mail exchangers, check priorities, and flag common misconfigurations.
- Blocklist checkQuery major blocklists for an IP address or sending domain.
- Inbox placement testSend one message to seed addresses across major providers and see where it actually lands.