Why is email to unknown recipients in my domain not forwarded to the postmaster?

Earlier POPcon versions before version 3.00 had no way of finding out which recipient addresses are configured in your Exchange Server. This caused email to such recipients to be bounced by Exchange. Unfortunately, Exchange has no option to accept all emails for a given domain.

But starting in v3.00 this feature is now available in the POP3 properties of POPcon - choose "re-route email to unknown recipients" and have POPcon route such email to your postmaster or administrator account.

The postmaster address configured on POPcon's "General" tab is only used for emails having no recipient in your "accepted recipient domains" at all and for emails initiated from POPcon itself.

If you do want your Exchange to bounce emails to unknown recipients back to the sender you can configure Exchange to send copies of the bounce messages including a copy of the original message to the exchange administrator.