Can ping Exchange server, can't connect Outlook to it

Question

I can ping the Exchange server here at work, but Outlook doesn't connect to it. I've verified the server is indeed the Exchange server and I've tried using the IP instead of the server name. I am also able to connect to port 135 using telnet (although nothing useful happens). I also tried running a trace using Wireshark but the protocols Outlook uses are proprietary and I couldn't see anything useful in the trace.

I'd love to hear some other steps I could take to track down the problem.

Solution 1

In our case the problem was with one of the routers along the way whose MTU was set to a low value. The packets sent by the RPC protocol were getting split and that for some reason prevented Outlook from working properly.

To determine the largest packet size that can get to the server, use the following command:

C:\> ping myserver.com -f -l 1500

Replace 1500 with different values to determine the maximum size of the packet. After you know the value, use the instructions here to set the MTU size for your network connection.

Solution 2

Use RPCPing - http://support.microsoft.com/kb/831051

Is this just one client that can't connect? Is it all of them? Does OWA work? (No point even trying to get outlook to connect if the server itself can't connect to mailboxes).

Are you sure you've installed all the correct roles on the exchange server? Is there a firewall or Antivirus software in the way somewhere (including on the server itself) blocking traffic?

Solution 3

The rectifications from microsoft didn't work for me. In the end created a new user profile for logon to windows. This fixed the Outlook 2010 connect to exchange server problem and also problem of having to keep supplying passwords to imap accounts. Presumeably my previous user profile was corrupted in some way.

Comments

[Gavin McTaggart]

Are all of the services running? What does the eventlog say? Is the Windows Firewall service blocking ports?

[splattne]

Are client and server in the same subnet/LAN?

[smassey]

My first question is which version of Exchange are you running? If you're running Exchange 2007 or 2010, are all of the roles running on the same server? Which version of Outlook are you trying to connect with?