Wiki · two references · free to read
When mail stops arriving, start here
A blocklist entry and a bounce code are the two things a mail server tells you when it refuses your mail. Each has its own reference, with the fix written out.
The references
- Blacklist wikiEvery blocklist that can stop your mail55 lists documented: what each one lists, what a listing costs you, and the steps to get removed. 33 of them are queried live by the blacklist checker; the dead ones stay, marked retired.55 lists33 checked liveOpen the blacklist wiki
- Error code wikiWhat your bounce message meansPaste a bounce and the lookup finds the codes, the provider and the entry that explains it. Standard SMTP codes and the ones providers define for themselves, each with the cause, the fix and its source.511 codes14 providersOpen the error code wiki
Beat · paid monitoring
A heartbeat for your email.
Beat runs every check on this site on a schedule: 41 checks, 33 blacklists and real inbox placement. The moment something breaks, it tells you what broke, why it matters, and the exact fix.
example.comWatching
- SPFpass
- DKIMpass
- DMARCp=none
- Blacklists0 of 33
Illustrative. Your domain, every few hours.
Also from us:Pulse: your own sending infrastructureConsulting: $65/hr, no retainer