The thing is if I decide to give Domain authority to may ISP all mail works well because I just ask for a MX record for mail server 188.8.131.52 and a host record for www.jfo.pt
What I am trying to do is get independent of ISP's and take control of my domain.
The thing is that it seems that my Ubuntu server is not letting go of the mails to the mail server and is checking if the users exist instead of simply passing them to the proper server to check. Is there any place to check outside of ISPConfig to prevent such behavior?
PS1: I am a MS Exchange specialist and can assure you that the MS Exchange is in perfect condition.
PS2: my var/log/mail.log.* files reach more than 3Gb. Is that normal or should I check those files to find some wrong behavior.