Well, I made a clean install of my Mail Server. Tested the tutorial on the link provided by Edge, but did not work out, I mean, the script did not capture the test mail I sent from my other Web Server.
After I made the clean install to a separate server, and moved all emails from the previous server to the new one, I again encountered the same problems. My server was sending too many emails. In fact, a hostmaster of one site, emailed me, informing me that one of his email users have receive an email which was sent from my server. Upon thorough checking of the said email, the email originated from a different server, and was passed through my mail server via a valid email address of my service.