PostPath Archiving and Filtering

In Exchange™, the MTA cannot be used for actions such as piping messages through a virus filter or archiving messages prior to delivery, requiring the use of proprietary mechanisms like the Exchange™-specific anti-virus API and the Outlook™/Exchange™ Journal.

In contrast, PostPath takes a standards-based approach focused on using the MTA (message transport agent) to archive or filter messages as required.

This has never been possible before because standards-based components (e.g. third-party virus filters) have supported only SMTP not Microsoft-proprietary ESMTP, and Exchange™ has required the use of ESMTP rather than SMTP if meta-data required for Exchange™ operation is not to be lost.

PostPath breaks open this transport-compatibility problem by supporting both ESMTP and SMTP, while at the same time enabling the SMTP traffic to losslessly carry with it all of the Outlook™/Exchange™ meta-data.

A simple illustration may help to clarify the point:

PostPath uses a modified version of the PostFix MTA to support these functions. PostFix is an open-source product, originally developed by IBM, that is one of the most widely deployed high-volume MTAs in use in corporations and across the Internet.