KB02050602 POP3 email routing suddenly stops working
Mail is being collected by POP3 from an ISP, and routed to the appropriate mailboxes within Mailtraq, however - with no changes in the Mailtraq configuration - the routing is no longer working correctly - messages are mis-routed and/or duplicate copies are being received
The key to solving this problem is to note that it went wrong with no changes in the Mailtraq configuration. This indicates that the root of the problem lies elsewhere, most probably with the ISP.
To find the cause of the problem we must first see how Mailtraq is configured to route mail arriving from the ISP.
In the Mailtraq Console select Options | Remote POP3 and view the Properties of the appropriate POP3 Mailbox.
Open the Message Routing tab and examine the options selected. You are looking to see what information in the message headers Mailtraq is using to decide which mailbox to route the message to.
The cause of the problem will likely be that the ISP has changed their mail server settings (or installed a new mail server completely) and the header information they were providing before is now being provided in a different way. There are few standards in this area, so it is not possible to list out all the alternatives, however careful examination of previously received (correctly routed) messages and current problematic messages should reveal the settings that are now needed in the Mailtraq configuration.*
Some ISPs do not provide the required information (the SMTP RCPT field) in whcih case it will not be possible for Mailtraq (or any other mail server) to route the mail to the intended recipient. The only solution then is to change ISP.
* See Collecting and Routing POP3 Email for detailed information on configuring your Remote POP3 settings.