Bruce Harrison wrote: >For the last month or two, I get anywhere from 3 or 4 to 20 to 30 postings to >non-existent lists on our mailman server. I've been reading of course about >the subscribe spamming that folks have been talking about. >Is this just someone poking at our mailman machine trying to find something to >send spam to, or something more sinister? We use Microsoft filtering for >spam, viruses, etc. so all mail I see comes from one of their servers. >It's not causing any problems, but just strange to me.
I haven't seen spammers subscribe to the lists properly (i.e, respond to the Mailman response), but I've had a lot of messages going to invalid users at the list domains and also to the subscribe/unsubscribe/request address, which was creating a lot of backscatter. >From my point of view I want to try and avoid accepting and processing spam >mail and mail to invalid lists/recipients to try and avoid backscatter. I >installed a local copy of SpamAssassin which seems to be working really well >and rejects spam over a score of around 7. This seems to let list traffic >through whilst blocking the spam messages. I also removed frontline MX >servers from the lists domain so they get handled by the Exim server doing the >processing, so that any 5XX response that the server sends out causes the spam >server to give up, rather than a frontline MX server having to generate the >NDR and send it out to the probably innocent party. To this end we used to >use MS Office 365 spam scanning on the list domains, but don't use it anymore >for this reason. Hope this helps, Andrew. ------------------------------------------------------ Mailman-Users mailing list Mailman-Users@python.org https://mail.python.org/mailman/listinfo/mailman-users Mailman FAQ: http://wiki.list.org/x/AgA3 Security Policy: http://wiki.list.org/x/QIA9 Searchable Archives: http://www.mail-archive.com/mailman-users%40python.org/ Unsubscribe: https://mail.python.org/mailman/options/mailman-users/archive%40jab.org
