Free deliverability tool
Email blocklist check
Blocklists are shared reputation databases that receiving servers consult before accepting mail. Being listed on a major one can stop delivery entirely, and on a shared IP you may be listed for someone else's behaviour.
Worked example — 198.51.100.24
Sample demonstration- PassSpamhaus SBL
not listed - PassSpamhaus PBL
not listed - PassBarracuda
not listed - PassSpamCop
not listed - PassSURBL
not listed
Clean across all five lists checked.
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
- Major IP blocklists — Spamhaus, Barracuda, SpamCop
- Domain blocklists — SURBL, URIBL
- Whether the listing is for the IP or a neighbour on a shared range
- Delisting route for each list that has you
Questions
Other tools
- SPF checkerCheck an SPF record, resolve every include, and count DNS lookups against the limit of ten.
- 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.
- Inbox placement testSend one message to seed addresses across major providers and see where it actually lands.