KB19061701 Archive Passthrough as POP3 Load Share
There is a limit on the number of Remote POP3 Collectors that are active at one time that a Windows platform will support.
To avoid hitting this limit, wherever possible you should receive mail direct via SMTP, or via a consolidated (catchall) POP3 mailbox and then use Mailtraq's ability to route POP3 mail.
If it is essential to have a large number of individual POP3 Collectors, and that number exceeds the number supported by your Windows platform, then you can work around the limit by installing a second Mailtraq on another machine, and use the 'Archive Passthrough' feature of Incoming Mail to collect by POP3 and then forward to the primary Mailtraq via SMTP.
General function of the 'Archive Passthrough' feature is explained here ...
In this use of the Passthrough, Mailtraq is installed on another machine.
Mailtraq is set up with the same Domain/s as the primary Mailtraq.
No mail is routed to the Passthough by SMTP. Mail only arrives by POP3 collection.
It is configured to have the required number of POP3 Collectors, each with a matching receiving Mailbox.
Each Mailbox Archive-tab is set to [x] Delete Messages Instead of Archiving them after 1 day so that the Passthough server does not fill up with messages. Remember to set a Maintenance schedule so that Archiving (Deleting) actually takes place.
Set Outgoing Mail to use a Smarthost and set the Smarthost to the IP address of the primary Mailtraq.
The expectation is that the Passthrough Mailtraq is sitting next to the primary Mailtraq on the same LAN.
Ensure that the IP address of the Passthrough Mailtraq machine is included in the LAN Definition of the Primary Mailtraq
Set the Archive Passthrough so that the Passthough Domain/s match the Primary and
[x] Copy all mail for local domains to Outbox
In operation the Passthrough Mailtraq will do a POP3 Collection from the remote mail server. That Collector will Route incoming messages to the mailbox on the Passthough Mailtraq AND place a copy in the Outbox.
The Outbox has been set to send all mail by SMTP to the primary Mailtraq.
The primary Mailtraq will route the 'copy' message to the matching mailbox.
The Archive operation on the Passthough mailboxes will remove the unneeded messages.