PostPath Server Archiving and Virus Filtering

Some of the applications that leverage PostPath's open-standards based architecture are archiving and virus filtering. Leveraging an open-standards approach increases the number of options that are available for both archiving and virus filtering.

As many are aware, Microsoft uses a "special" version of SMTP called ESMTP when Exchange is talking to other Exchange servers. From an open standards perspective, this is a Microsoft-only form of SMTP and has the effect of making it impossible to pass emails through standard virus filters. It also makes it very difficult to forward emails to SMTP-based archive "sinks" from Exchange, leading to the use of expensive and inefficient Journaling based archiving solutions.

To solve this problem and allow the use of standard SMTP, the PostPath Server can translate the Microsoft ESMTP to legal SMTP; where appropriate the PostPath Server can also convert in the other direction as well - and it can convert from SMTP to ESMTP and back without loss of metadata.

For virus filtering as an example, we convert to standard SMTP, filter through a standard virus filter (possibly a commodity virus filtering appliance or virus filtering service), get each message back, convert it back into the Microsoft format, and drop it back into the Microsoft world.

Our plug-compatible solution does this without any loss of Microsoft metadata. This allows our customers to leverage the much more scalable and cost effective virus filters that exist for standards based SMTP. This approach has the additional advantage that virus-processing is carried out outside of the main line of execution of the server, making the server much less vulnerable to virus filtering latency during times of heavy load.

Similarly, for archiving software, we can forward a copy of each message to the archive utility at the MTA (Mail Transport Agent) level, before the message is deposited into any store. There is no need to use Journaling, and archiving can be turned on or off on a per-user, per group, or per server basis. Again, this is possible because of our standard Unix-style MTA architecture, a standard architecture that is not available for Exchange users.