Strange Postfix Problem

[Dogberry1982]

I am encountering a very strange problem with my Postfix server. I setup this server at the beginning of the month as a front end server for our Exchange server.
It has been up and running since then and seems to be working correctly, however certain users outside are unable to send email to some of our users.
I know it is not a DNS issue because these same users are able to send email to my email account (on the same domain) with no problems.
The strangest part is that there are NO references to the emails in the Postfix logs.
If my understanding is correct Postfix logs ALL activity regardless of whether the email is delivered or not. But when I search the logs there is no reference to the emails that our users did not receive.
I can find the references to the email they are sending to my email account that comes through, but the email that they send to the users that are not receiving the email is never logged.
These same users of ours can receive email from anyone else, it is just a specific account outside that they can’t receive from.
Again these same users outside can send mail to me with no problems. In addition our users can send mail to them, even the reply’s they send are not coming through and are not referenced in the logs.
Does anyone have any idea what might cause this?

I have wracked my brain, looking down the list of possible causes and I can’t find anything wrong. I would understand if the email were getting blocked for some reason (which would be logged), but there are NO records of the emails in the logs.

Mason McElroy

[Touchtecservers]

Are the email addresses that fail on the same domain as the email addresses that work?

And is there any filtering going on prior to postfix receiving these on port 25?

[Dogberry1982]

The accounts are on the same domain, and there is no filtering before the Postfix server.

Thanks

Mason McElroy

[Touchtecservers]

Maybe try turning up the logging level on the postfix server?