Re: problem with spam

[Christos Chatzaras]

Thank you everyone for the replies. I think I found the problem. The spambot 
(uploaded by hacked websites) does direct connections to port 25 to other mail 
providers. That's why I don't see any logs for outgoing e-mails but I get 
backscatter from hotmail and other providers. I will try to use the firewall to 
allow only outgoing connections to port 25 from postfix's uid and not from 
other user accounts. I think this will fix the issue.