Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

When outlook 2003 is setup with an Exchange 2003 server, within an internal network, and with 'Microsoft Exchange Server' as the 'Server Type', what port(s) are used?

Also, if it is a bunch of ports but it can be bound to specific port on the server side, where would I check if this had been done?

share|improve this question
up vote 4 down vote accepted

There is an initial communication from the client (on an ephemeral port) to the server's TCP port 135. The server's RPC endpoint mapper establishes a random port on the server and sends that to the client and then the client connects to that random port.

Here's an article from Microsoft that talks about what you'd need to do to establish static ports on the server:

If you want to quickly see if the server has this configured, go have a look at HKEY_LOCAL_MACHINE\System\CurrentContolSet\Services\MSExchangeIS\ParametersSystem and look for a value called "TCP/IP Port". (That's only one of the places where it would need to be set. The article can tell you the rest.)

(If you're looking for this to forward Outlook-to-Exchange communication across a firewall for a large number of clients think about using RPC-over-HTTP(S) (also known as "Outlook Anywhere") in lieu of making this change. If not, forget that I said anything...)

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.