Spamhaus Problems

Well here we are on another day sending emails as you do. I notice however that today we are having huge numbers of them deferred. The lists are fine, all the DNS entries appear to be OK, we are not black or grey listed what is going on?

Looking at the sendmail send logs I see lots of "=Deferred: 451 http://www.spamhaus.org/query/bl?ip=nnn.nnn.nnn.nnn" messages. So far so good, not blacklisted, but what is going on.

So I head over to the Spamhaus site and... uh oh it's slow, slow, slow. What seems to be happening is that the email servers we are sending to are trying to look up our IP in Spamhaus, which isn't responding so they are probably timing out and deferring on us. Which means that we will back off for a while, then try again, causing more traffic, more lookups on Spamhaus, and legitimate emails from our clients to be delivered late.

Now, don't get me wrong, Spamhaus is a fine organisation with laudable aims and doing a fantastic job. It's just frustrating that we get caught in the crossfire.

It would be good if there was some way of knowing if Spamhaus were suffering a DDos or similar, then we at least could let our clients know etc.