What is ZapBL?

dnsbl.zapbl.net checks IPs and rhsbl.zapbl.net checks domains. The ZapBL Team runs them.

What the operator says

"merely a list of opinions of the administrators" ZapBL, read 1 Nov 2026.

What it really measures

Mail that reached the team's own addresses, spam traps included, and that they judged to be spam. They say this is an opinion on where they do not want mail from, and that they are not calling anyone a spammer. Domains advertised in that mail can be listed too.

Why you might be there

By the team's rules, one of these happened:

• Your IP sent unsolicited mail to one of their addresses.
• Your system auto-replied to spam or viruses. They list that on purpose, because those replies land on people whose address was forged.
• Your domain was advertised in spam.
• A neighbour was listed. Three listings in a block of 256 neighbouring IPs widens the listing, and it can grow further.
• You provide web, DNS or mail services to a spammer.

What to think about

Check your auto-replies first, because that one is easy to miss. If the listing widened from your neighbours, your provider is the one who can solve it.

How to get off it

Most listings expire by themselves. Use the lookup, which shows a removal option when there is one. If not, send your reasons through the site's contact page. They only accept this from the registered contact for the IP block, so end users go through their provider. Express delisting with a manual review also exists.

Want a hand getting this delisted? Here is how to write to a list's operator, or ask a person on our free SOS Hotline. Tell us the list and the IP or domain, and we reply within 48 to 72 hours.

A separate job: cleaning your list does not remove a listing. If you also want to know who on your list is safe to send to, clean your first 1,000 free.