Troubleshoot connecting to Exchange server using HTTP

• Your Exchange server administrator has not configured this feature. For more information about configuring this, see the Microsoft Office Resource Kit.

• You may not be running Microsoft Windows XP Service Pack 1 (SP1) with Microsoft Knowledge Base article 331320 updates installed or later.

You may have an incorrect Web address, certificate principal name, or authentication type for the Exchange proxy server.

1. On the Tools menu, click E-mail accounts, select View or change existing e-mail accounts, click Next, select the Exchange e-mail account, and then click Change.
2. Click More Settings, then click the Connection tab.
3. Under Exchange over the Internet, select Connect to my Exchange mailbox using HTTP.
4. Click Exchange proxy settings.
5. Under Connection settings, in the Use this URL to connect to my proxy server for Exchange box, type the URL provided by your Exchange server administrator.
6. Under Connection settings, in the Principal name for proxy server box, type the principal name provided by your Exchange server administrator.
7. Under Proxy authentication settings, in the Use this authentication when connecting to my proxy server for Exchange list, select the authentication method provided by your Exchange server administrator.

Also, your computer may not trust the Secure Sockets Layer (SSL) certificate of your server. Browse to the address listed in your configuration page and add /rpc to the end. If you are prompted to trust a certificate, select Yes (only if you know that you are connecting to the correct server).

For example, if your address was mail.example.com, you would type https://mail.example.com/rpc into your browser. If using Microsoft Internet Explorer, you will be prompted to trust the certificate if it is not already trusted.

1. On the Tools menu, click E-mail accounts, select View or change existing e-mail accounts, click Next, select the Exchange e-mail account, and then click Change.
2. Click More Settings, then click the Connection tab.
3. Under Exchange over the Internet, select Connect to my Exchange mailbox using HTTP.
4. Click Exchange proxy settings.
5. Under Connection settings, check the Connect using HTTP first, then connect using my Local Area Network (LAN) check box.