By Diane Poremsky
As anyone who has ever used Outlook with an IMAP account knows, Outlook doesn't handle IMAP accounts well. The most irritating issue is how it copies sent messages to the local message store instead of the Sent folder on the IMAP server. You can use Rules to copy the sent message to the IMAP Sent folder, but you'll still have a copy of the item in the local folder. You can turn off the option to "Save copies of messages in Sent Items folder", but if Outlook is unable to connect to the IMAP server for whatever reason, a copy is not saved.
To set up the rule, go to Tools->Rules and Alerts (or Rules Wizard). Create a new blank rule, and then select Check messages after sending. Select a condition if you want to copy certain items to the IMAP folder, or leave it blank to copy every item you send. Now click Next.
Choose "Move a copy to the selected folder" as the action and select the Sent folder on your IMAP server, then click Next. Set up any exceptions you want and click Finish. Now all messages you send, or those meeting the conditions you selected, are copied to the IMAP server. If you have two or more email accounts and disable saving sent items, you'll need to create rules for the other accounts if you want to save the sent messages.
If you don't want a second copy locally, open Tools->Options->Preferences->Email Options and remove the check from "Save copies of messages in Sent Items folder". If you have more than one account, you should create a rule for each account, otherwise all sent items are moved to the IMAP server's Sent folder.
A Knowledge Base article details this method using a condition of "messages using the Message form" so that it applies only to messages, not task or meeting requests. Although it says it's for Outlook 98 in Internet mail only mode, the same technique works for all versions that support IMAP accounts. The Knowledge Base article, "OL98: (IMO) How to Save Sent Items on an IMAP Server" can be found at http://support.microsoft.com/?kbid=198852.
