Strange entries in Maillog

hi,

i need an advice interpreting some entries in my maillog.

we got one mail from outside that was sent to 3 people from our company.

that mail had a trojan in it.

i wonder why that mail could be delivered.

in the log it has a random address like “xxxrobomail@mydomain.com”.

and that email address does not exist at my domain.

so is there a way to prevent my mailserver from getting those “spam” mails?

i can not exclude the smtp-server, because it’s one of the biggest german business provider, and perhaps we get some expsensive mails from there, too.

here is the log entry:

17.01.2004 23:08:05 SMTP Server: hnvr-d9b8e9a9.pool.mediaWays.net (217.184.233.169) connected

17.01.2004 23:08:39 SMTP Server: Message 0079A45F (MessageID: 66462994217872.80819robomail@mydomain.com) received

17.01.2004 23:08:39 SMTP Server: hnvr-d9b8e9a9.pool.mediaWays.net (217.184.233.169) disconnected. 1 message[s] received

regards, wolf