Outbound Spam Filtering
I am writing here as I am trying to find some possibilities to filter outgoing messages contain spam or malwares. We have lately got a lot of rubbish being sent out from our servers we use both DirectAdmin and cPanel and we would, preferably, a filtering method working on Exim on dedicated environments (such as 2-3 dedicated servers at the edge).
We have not found a generic solution that can help filter outgoing spams. We have all cause of spam, such as user compromised accounts (aka Ive got a Trojan on my computer), we have also the I dont update my Joomla! (aka I code like a nut and dont update my scripts ever so my site get owned with multiples RFis and spam sent by tons).
We have implemented hourly/daily rate-limit and we contact each compromised account one by one, figuring out the source of the spam. Only once solved we reactive the account. However, even with 60 emails/day, some user managed to get our servers listed in some RBLs.
No need to blame us, we are trying to solve this. How do you address this issue on your network? Does anybody have a good solution to filter outbound spam with low maintenance overheads once setup? Any advice welcome!
Greg
