There are times you want to use an application that will allow you to retrieve the UID from an IMAP server. The UID is managed on the IMAP server but is not updateable by an IMAP client such as Outlook. However, as an administrator, you might find it useful to be able to read the UID. If the application is written to save the UID then this will give you the capability to perform state comparison based synchronization the next time a login to the IMAP server is performed. The state comparison based synchronization can leverage the UID, message flag and content for its analysis.

Unfortunately, there is the possibility that you will receive errors such as the “MAPI_NO_SUPPORT” error message. This has been known to happen when Outlook makes calls to the GetIDsFromNames function or the GetNamesFromIDs function on an IAttach interface for a secure message such as a signed message or an encrypted message. Outlook will sometimes quit when this occurs.
 
It is important to understand the mechanics underneath an application that is used to look up information about end users. Especially when looking up the information – such as a UID – can cause a problem.

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