Hello everyone,

I'm running into a strange connectivity problem with the Spamhaus RBL.

I'm running Debian / Exim.

I've configured Exim to use 2 RBLs – Spamhaus (zen.spamhaus.org) and Spamcop (bl.spamcop.net). Spamcop is working fine, with it rejecting an email roughly every few minutes. However Spamhaus only appears to be working fine some of the time – e.g. it will reject emails roughly every few minutes for a few hours, then not reject anything for a few hours, over and over again. Its worth noting the problem starts / stops randomly, not at the same times each day.

Given Spamhaus is a bit more of a thorough RBL than Spamcop, a significant number of spam emails are getting delivered during the Spamhaus "downtime".

I think this started happening maybe a month or two ago. Before that both RBLs were working fine. I haven't made any changes to the Exim config in about a year.

Does anyone have any idea what's going on here?

There doesn't appear to be anything of note in the '/var/log/mail.log' or the '/var/log/exim/mainlog'.

Any help would be greatly appreciated.
.