Thanks for all your comments!
September 28, 2007 10:00 am GeneralThanks for all the comments – it appears the 3 first hours were the worst, and I only ended up with around 3000 bounces to handle, plus a few stragglers now. It’s a pity, because now libregraphicsmeeting is going to be on every spam blacklist for a few months. But it appears it was a smallish spam run in the end.
For info, removing the MX record from the zone file didn’t take – not sure why, I’ll have to ask Verio about that. So for now the only thing I’m going to do is suck it up, and hope it doesn’t happen again.
September 28th, 2007 at 10:27 am
You should consider setting an SPF Sender Policy text entry in your MX records. If you had done that beforehand, you would probably not have had this problem.
September 28th, 2007 at 12:23 pm
IIRC having no MX is legal according to the email RFCs. MTAs will in that case just try to deliver on your A record for the domain. I think.
September 28th, 2007 at 3:49 pm
Like the guy above said, configure SPF. Also, check out domainkeys. Most spam ends up going to ISP’s that actually properly check this stuff, so they should reject any email from your domain that’s not getting sent from your server.
October 6th, 2007 at 11:05 am
damn, I missed that — here’s how to fix that problem, in case it happens again: http://taint.org/2007/05/30/164456a.html
October 6th, 2007 at 11:06 am
btw, the presence (or lack) of an SPF record would be irrelevant. the sites sending you these bounces don’t bother checking SPF beforehand.