How to setup outgoing spam block ?

Hello to everybody,

searching in virtualmin guide, on this forum and on google I can’t find a way to setup a filter that block outgoing spam.

I have two problems related to outgoing spam:

  1. sometimes some malware (in users PC) intercept credentials and sends spam with hacked users accounts on my server…OVH spam filters intercept messagges and block my SMTP 25 port

  2. mail forwarding, setted on users account, forward inbound spam to external address. This traffic is intercepted by OVH spam filter that blocks my SMTP 25

For me is important to prevent OVH blocking…There is a way to do this ?

Mail rate limit is a useful help (especially in first case), but not enough to avoid OVH network filters blocking…


For me is important to prevent OVH blocking…There is a way to do this ?
Yes, suspend your client account and ask them to repair their website, change their login info, you can repair for some fee, if they are unable to repair and dont want to pay you then terminate their account. You should make money from them and not pretend you are charity.

I think your client website got compromised or their Vmin login details, but usually the culprit is hacked website. Other ways to prevent outgoing spam is to limit emails for that account or even stop entirely, editing postfix (not recommended on live server), installing some extra stuff to check postfix and outgoing emails (not recommended on live server).

Either way first you must check log files, see how that spam was created and then decide what is the best solution.

P.S. Dont forget to check your postfix is not running an open relay.