You would think that when your email client saves a copy of an outgoing message in your “Sent Items” folder, that message would be an accurate copy of the message that was sent, right?
Well, in the case of Microsoft Outlook and IMAP, you’d be wrong.
For some entirely inexplicable reason, Outlook assigns one message ID (i.e., the contents of the “Message-ID:” header field) to the message that it sends to its intended recipients, and a different message ID to the message that it saves in your Sent Items folder.
How anyone at Microsoft could think this behavior is reasonable is beyond me.
It prevents Outlook or any other email client from accurately tracking, or threading, conversations.
It prevents automated processes, such as the tool I previously wrote for automatically filing sent items, from working properly.
It makes it impossible for system administrators to accurately track and research mail delivery issues, because the users who sent the problematic messages can’t provide them with the correct message IDs to look up in the logs.
My next blog entry will detail my solution to this problem. Stay tuned!