recently my server always down, after checking found user spam mail

[seachen]

i found out user using email bombing script send out a lot of spam mail.

may i know how to prevent this ?

 

[nobaloney]

Hopefully your Terms of Service allow you to suspend/remove your user.

You can check the size of your queue from time to time; if your users are spamming you'll see a huge increase in your queue size.

You can also set up an account with the AOL postmaster (http://postmaster.aol.com/) to notify you if anyone is spamming their users from your server.

Jeff