Most ISPs block port 135 connections which is the default connection used by Exchange and Outlook.  Outlook 2003 and 2007 support RPC over HTTP connections which allow remote users who have Exchange Account on our service to connect to their Exchange account using Outlook 2003 or 2007. 

•  Configure Outlook as normal.  If you have already created your Exchange Profile in Outlook, go to Tools, and Accounts and change your account
  • This will display the Exchange server settings. 
  • You must first enter the server name of the Exchange server you will connect to.  (your ISP will provide this)
  • Enter your username
  • Click on the More Settings button
  • Select the Connections Tab
  • Put a check in the Connect to my Exchange mailbox by HTTP
  • Click on the Exchange Proxy button
  • In the URL field, enter the URL of our Exchange server that you are assigned to.  (often the same as your Exchange server name)
  • Put a check on both the "on a fast network" and "on a slow network".C
  • Change Authentication to Basic.
  • Click on OK all the way back out.

This will now cause your Outlook to not use port 135 but use port 443 to connect to our Exchange server.

One last issue has to do with the login.  When you start Outlook you will be prompted for a username and password.  The username must be put in as domain\username.  Your ISP will provide the correct domain name.