More and more companies are allowing employees to work from home via remote offices. Outfitted with high-speed internet, separate phone lines for fax and business calls and office white boards and most office workers are ready to be productive as if they were working in any office environment complete with interruptions – though not the usual kind.

One of the interruptions remote office employees will most often face is that of remote connectivity problems. The problem of a remote connection being down is that it is sometimes hard to pinpoint the exact cause of the remote connectivity issue.

For instance, users have reported remote connectivity problems when running Exchange 2003 on a Windows 2003 Enterprise Server. Remote users will experience “disconnected” status issues when connected remotely and Outlook will be displayed as being in “offline” mode. However, when users are in their company’s office they do not have any problems connecting to their Exchange mailbox while using Outlook 2007. And running in cached exchange mode does not appear to help either.

One of the first steps that an administrator should perform is to verify whether the Virtual Private Network (VPN) is working correctly or whether it is part of the problem. An administrator can bypass the VPN by configuring Outlook to communicate with the Exchange server via Remote Procedure Calls (RPC) over Hyper Text Transfer Protocol (HTTP). This will allow the administrator to confirm whether the remote communication problem still exists even when not using a VPN connection. If there is still a remote connection issue, while running RPC over HTTP, then the administrator will know that VPN is not part of the problem.

Running RPC over HTTP is a method used for passing email traffic over the ports normally used for web browsers. Using this method, Outlook MAPI client users are able to access their Exchange server email accounts from remote locations even if the server and the client are on different networks and behind their respective firewalls.

For this to work, administrators will need to setup an RPC proxy server that is used to specify the communication ports for network domain controller, global catalog (GC) servers and the Exchange server that will be used by the client. In addition, the Exchange server(s) must be configured to use RPC over HTTP and user account(s) must also be configured accordingly as well.

Administrators should follow the steps outlined below in order to configure Outlook clients to use RPC over HTTP.

1. Click on the Start button and then right click on the Outlook 2003 icon and then click on Properties.
2. Click the Add button in the Mail dialog box.
3. Type the profile name in the Profile Name text box.
4. Click OK.
5. Select “Add a new email account” option.
6. Click Next.
7. Select the Microsoft Exchange Server option from the Server Type page and click Next.
8. On the Exchange Server Settings page, type the Fully Qualified Domain Name (FQDN) for the Exchange Server in the text box.
9. Type the user account name in the User Name text box.
10. Click the Check Name button to confirm that the Outlook 2003 client machine can communicate with the Exchange Server.
11. Checkmark the “Use local copy of Mailbox” checkbox.
12. Click the More Settings button.
13. Click the Advanced tab and confirm that there is a checkmark in the Use local copy of Mailbox checkbox.
14. Click the Security tab.
15. Checkmark the “Encrypt information” checkbox.
16. Click the Connection tab.
17. Select the Connect using my Local Area Network (LAN) option.
18. Checkmark the “Connect to my Exchange mailbox using HTTP” checkbox.
19. Next, click the Exchange Proxy Settings button.
20. In the Exchange Proxy Settings dialog box, type the FQDN of your Exchange Server in the Use this URL to connect to my proxy server for Exchange text box. (Note: This is the Common Name as listed on the Web site certificate.
21. Checkmark the “Mutually authenticate the session when connecting with SSL” checkbox.
22. Type the FQDN of the Exchange Server (see your Web site certificate) in the Principal name for proxy server text box. (Example: Msstd:FQDN)
23. Checkmark the “Connect using HTTP first, then connect using my Local Area Network (LAN)” checkbox.
24. Select the Basic Authentication option from the “Use this authentication when connecting to my proxy server for Exchange” drop down box.
25. Select the Basic Authentication option.
26. Click OK in the Exchange Proxy Settings dialog box.
27. Click Apply and OK on the Microsoft Exchange Server dialog box.
28. Click Next on the Exchange Server Settings page.
29. Click Finish on the Congratulations! Page.
30. Click OK on the Mail dialog box.

After making all these changes you should then be able to open Outlook and confirm the connection status as “online” to your Exchange Server. If you are able to perform a successful connection here then your problem is not with the Exchange server but somewhere in the VPN connection.