Mail servers decide whether to trust your mail based on the reputation of the IP it comes from and the domain it claims to be from. The fastest way to wreck that reputation is a blacklist listing, so that's what this check looks at first.
Free, no signup. See if Spamhaus, Barracuda, SpamCop, or other major blacklists have you listed.
Examples: 203.0.113.42 or example.com
| Blacklist | Status | Response |
|---|
Hundreds of lists, and one listing is enough to get your mail rejected.
Google rates your domain on spam complaints and sender requirements. Google Postmaster Tools monitoring
Microsoft rates your sending IPs green, yellow, or red. Microsoft SNDS monitoring
Generator Labs monitors your IPs and domains against hundreds of blacklists, plus Microsoft SNDS and Google Postmaster Tools on paid plans, and alerts you when your reputation slips. Free for your first host.
IP reputation follows the server sending your mail; domain reputation follows your brand wherever you send from. Mailbox providers weigh both. More in IP reputation vs domain reputation.
Usually spam sent from it, by you, a hacked account, or a previous owner of the IP.
Stop the cause, get delisted from any blacklists, and keep sending clean mail. Reputation recovers over days to weeks.