MTA Improvements in Exchange 5.5

Here are some features to look for in the MTA in Exchange 5.5:

  • Improved attachment interoperability.
  • Better queue scalability (gained by splitting one queue into seven).
  • A more scalable and faster MTA database in restart and recovery situations.
  • Delivery restrictions and content-length checking for messages sent to custom recipients.
  • Leverage of Remote Access Service (RAS) multilink support; RAS will no longer be a bottleneck for other transports within the MTA.
  • Support for the Mail and Directory Management (MADMAN) Management Information Base (MIB) counters in Perfmon.

In addition, Exchange 5.5 tweaks performance in other areas and fixes the usual quota of bugs. You probably won't notice the changes in MTA performance unless you use RAS to connect servers or build very large servers that process many thousands of messages each day.