Forum Moderators: DixonJones
216.209.172.182 - - [30/Aug/2002:13:20:00 -0400] "CONNECT smtp1.sympatico.ca:25 HTTP/1.0" 200 4640 "-" "-"
216.209.123.134 - - [30/Aug/2002:13:20:07 -0400] "CONNECT smtp1.sympatico.ca:25 HTTP/1.0" 200 4640 "-" "-"
206.172.206.236 - - [30/Aug/2002:13:20:18 -0400] "CONNECT smtp1.sympatico.ca:25 HTTP/1.0" 200 4640 "-" "-"
It is likely that this is a spammer trying to mask where they are sending their spam from.
It's simple - they find a HTTP/CONNECT proxy (like your server) through port scanning and then proxy all of their SMTP traffic though your server to cover their tracks.
CERT has issued a vulnerability alert about this. You can find it at [kb.cert.org...]