Symptoms:

After you move or copy a folder that was created in an Internet Mail Access Protocol (IMAP) folder tree to a Messaging Access Protocol Interface (MAPI) folder tree, you lose some of the functionality of the IMAP folder, such as the ability to delete new messages. A MAPI folder is either a personal folders (.pst) file or a mailbox on a Microsoft Exchange Server.

Cause: 

This behavior is by design. 

Workarounds:  

I. Use the following steps to work around this behavior:

  1. Create a new folder in the MAPI folder tree.
  2. Copy all items from the IMAP folder to the new MAPI folder. 

Note: Do not copy the entire folder from the IMAP folder tree to the MAPI folder tree.

II. Contact Support and reference this Knowledge Base article. Inform us of the mailboxes affected by this issue, and our senior engineers can change the attributes of the folder on the server to remedy this problem.

More information: This behavior occurs because all of the IMAP features, such as the View and Edit menu options, are carried over to the new folder tree. Many IMAP features do not work in a MAPI folder tree. For example, if you use the feature to purge all marked items for deletion, you may receive the following error message: 

The Operation Failed. 

The error message does not indicate why the operation did not work or how to resolve the issue. For more information, you may refer to the Microsoft Knowledge Base: http://support.microsoft.com/kb/304043.