Backscatterer doesn't list spammers. It lists mail servers that send bounces or auto-replies to forged sender addresses, which lands junk mail in innocent people's inboxes. Big providers get listed too.
Spammers forge sender addresses. If your server accepts a spam message first and bounces it later, or sends an out-of-office reply to it, that bounce goes to someone who never sent anything. Sender address verification callouts count too.
Reject spam and unknown recipients during the SMTP conversation instead of accepting and bouncing later, keep auto-replies away from spam, and turn off sender callouts. Once it stops, the listing takes care of itself.
Backscatterer removes an IP automatically four weeks after the last backscatter it sees, and every new incident restarts the clock. It also sells express delisting (89 CHF when we checked in September 2026), but it's never required, and the operator doesn't make exceptions on request. Check your IP on Backscatterer.
Backscatter listings often mean a mail server setting nobody has looked at in years. Generator Labs checks your IPs against Backscatterer and hundreds of other blacklists and alerts you by email, Slack, SMS, or webhook when a listing appears. Free for your first host.
Four weeks after the last backscatter, free. Each new incident resets the clock.
No. Express delisting is optional.
No. It means your server sent bounces or auto-replies to forged addresses.