What is the InterServer blocklist?
Still have a question, spotted an error, or have a better explanation or a source we should cite?
rbl.interserver.net checks IPs. Its site now carries the MailBaby name, and we class it as low-impact.
What the operator says
"servers which have brute forced (ssh, ftp, pop, imap, passwords), spammed" MailBaby, usage guide, read 1 Nov 2026.
What it really measures
More than email. It tracks servers that tried to break in by guessing passwords, sent spam, or tripped a web security filter. An IP has to be seen doing this on several servers before it is listed.
Why you might be there
Something on that server may be guessing passwords or attacking websites, and your mail may be fine. If several IPs nearby cause abuse, the whole block of 256 can be listed until those expire.
What to think about
Look at the whole server, and at more than your mail.
How to get off it
This list holds entries for 5 days before they expire, so fix the cause and wait. Its IP page has a search and a contact link.
What "low-impact" means on these pages: the big mailbox providers rarely use the list, so it rarely affects delivery at Gmail, Outlook or Yahoo. It can still point at something worth fixing.
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.
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