Command Center

1. verify Squirrelamil -> Options-> Folder Preferences -> Sent Foler: Sent

2. Enable IMAP on Outlook 2007 for both machines

3. The first time you send an e-mail message with your IMAP account, you are prompted to choose the folder where you want sent items saved. Pick custom Folder -> mail->Sent

OR
   1. On the Tools menu, click Account Settings.
   2. Select an e-mail account that is not an Exchange account, and then click Change.
   3. Click More Settings.
   4. In the Internet E-mail Settings dialog box, click the Folders tab.
   5. Click Choose an existing folder or create a new folder to save your sent items for this account in, expand the folder list, and then click a Folder -> mail->Sent

4. Click Send/Receive button on the other machine. Now, both machine and SquirrelMail should contain the e-mail.





References
http://office.microsoft.com/en-us/outlook-help/change-where-sent-e-mail-messages-are-saved-HA010164216.aspx
http://www.entourage.mvps.org/database/sync.html
http://www.sevenforums.com/browsers-mail/45179-how-save-sent-items-imap-server-live-mail.html
http://www.question-defense.com/2009/03/05/in-outlook-2007-save-copy-of-sent-pop-account-messages-to-gmail-imap-sent-folder
http://www.msoutlook.info/question/486
http://www.ehow.com/how_4831673_save-sent-emails-imap-folder.html