I have PostFix setup in Ubunut 10.04 and relay's working fine and able to send out emails.
However after recieving emails from PostFix to a regular email client (ie Outlook), I see this in the return sender address: firstname.lastname@example.org
In which when a client responds to this message, it give a bounced back error obviously:
Your message could not be delivered to one or more recipients. It's attached below.
For further assistance, please send mail to postmaster.
If you do so, please include this problem report. You can delete your own text from the attached returned message.
The mail system
<email@example.com>: Host or domain name not found. Name service error for name=monitor22.csaa.local type=A: Host not found
Question is how can male PostFix to recieve emails?