spammer using my mail server send spam email
 

there days, i found one spammer who sent a lots of spam mails via my email server

i have configured sendmail with auth for relay, i don't know how does spammer can do it?

if he cracked my user's username&password, how can i track it in log file /var/log/maillog ?? there are no "authid= ??" in the log file. very stranges

hope someone can help me.
thanks a lot

First up, consult this link to MAPS TSI Anti-Relay. If the spammer is still able to relay after following the config guide for your MTA, post what you have configured so far (as in the config file changes and how you applied the changes) and post some sample log entries of the spammer sending messages.

thanks