Today my server was listed in cbl. I write them and they say this: Your server, in short, is HELO'ing (identifying itself during the HELO phase of the SMTP conversation) as the domain of the host it is connecting to, but only occasionally. This makes me think that it's not your MTA, but some other software or process. It's not a volume issue, it's that it is incorrect to HELO as the domain you are connecting to, and such behavior is extremely suspicious and a very reliable sign of virus/trojan infection. So, you need to figure out what process is doing that. I suggested fetchmail may be the culprit earlier - are you running fetchmail? Please how can i fix the wrong HELO.