Normally in your mail setup you should see the word IMAP or POP in the outgoing address. If it's IMAP try setting up an alternative mail client and looking at your mail to see what you have.
Is Outlook set up to remove messages from the server or not?

Try searching for "remove duplicates outlook" in Google to see how it should be done ( and perhaps why there are so many duplicates)

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Yes, it is IMAP.


I've manually solved the problem of the duplicates, and new messages are coming singly, as they should. Outlook is removing deleted messages from the webmail server. It also added back the emails I rescued from Trash (ex-duplicates) but gave them all yesterday's date and shows they all came from me - so they're totally out of sequence and I can't see who they're from.


Sometimes I just hate computers!



What I'm really upset about is the loss of four years' emails - a period when I was doing a lot of research and there was some gold in amongst them.


And what I don't understand is how they could all be there on day one, and disappear, then re-appear, then seemingly permanently disappear on day 2.