Is my server being used as relay? (mail log file included)

if so, how do I stop it?

[walkman]

On my mail log I see some "relaying denied" entries but then I saw this:

Mar 16 08:45:47 myservername sendmail[15652]: m2GCj*****: from=<*****@randomdomain.com>, size=0, class=0, nrcpts=0, proto=SMTP, daemon=MTA, relay=[IP.***.***.**]

Is my server being used as a relay? If yes, how do I stop it? I use sendmail /webmin.

any help would be greatly appreciated, as this might get me in trouble with ISPs.

[Receptional Andy]

Have you missed off any of the log line? I don't see what action the server took.

[mcavic]

That from= line is just the attempt. If it's accompanied by relaying denied, it's fine. If the attempt was successful, there would be a to= line with the same m2GCj* message ID.

[walkman]

thanks guys, I will check it.