In my administrator daily report I can see that someone is spamming through my server.

Most active senders
XXXXXX
2 jobnet@ams.dk
2 info@shapex.eu
2 bounce_79db54a0b2408fa8a98f843e83cb@...tromail s.com
1 japanesev42@schatz.de
1 fatties@sermicro.com
1 prepositioning@santiagoecintra.es
1 rapprochementsu2@securita.pl

I am not sure why they are able to send through my server, but i was told that one of my users probably have a virus of some sort.

I know that I should look at the log file, but I donít know what to search for.

I have tried to search the forum, but i dont know any keywords for my problem.

Please, help me find the leak.