No incoming mail

[Rupert Reid]

As you can imagine from the question I am asking I am new to postfix,  
however, I hope that the many experts among you will be able to help  
me resolve this problem.  I have configured postfix for my domain and  
everything seems to check out fine. I am able to send emails and when  
I send emails via (from the same machine) "# telnet mail.example.com  
25"  The email is delivered.  However, if I send emails from a  
webmail MTU the mail does not arrive - no log in the mail.log  - the  
MTU reports that the message has been sent and there is no bounce  
back to the sender.

Regards
Rupert