Prevent a specific user from sending emails?

Question

linux

Hello!
One site got infected on my server and started, as usual, spamming.
The site is launched in fcgi mode on behalf of its own user.
I do not want to turn off the site during the cleaning. It is better to turn off mail for that user.
Tell me how to do it? In a postfix somewhere, or somewhere else?
Thank you!

Answer 1

or a firewall. or disable the account if it spams through a controlled mail server.

Answer 2

If the site is in php, try enabling safe mode and disabling mail sending functions

Answer 3

http://myconsult2.blogspot.com/2009/11/postfix.html
http://www.bezopasnik.org/unix/dok/Soft/postfix/19.htm