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Mike_AP's avatar
Mike_AP
Copper Contributor
Sep 19, 2026

New Outlook extremely slow to sync IMAP accounts

Hello - I am finding New Outlook extremely slow when syncing a couple of IMAP accounts, @yahoo.co.uk and btinternet.com. It can take hours, even days, although it does eventually catch up. A manual View\Sync brings up the "Syncing..." popup, but does not actually sync. This seems to have started following the outage in late August, and is happening on two devices. I have removed and re-added one of the two accounts affected with no improvement. Classic Outlook and Outlook for Android are working normally, as are two Exchange accounts on the affected New Outlook clients. My work-around is, of course, to switch back to Classic Outlook, but can anyone please suggest how this might be fixed in New Outlook? Thanks.

3 Replies

  • mbriscoe's avatar
    mbriscoe
    Tin Contributor
    Sep 20, 2026

    Is it possible to change the default to 'Classic Outlook' so you do not have to start with the new  and change to Classic Outlook?

     

     

    MB

    • Mike_AP's avatar
      Mike_AP
      Copper Contributor
      Sep 20, 2026

      Thanks MB - yes, no problem starting Classic (in fact I'm now running New and Classic side-by-side). It would just be nice to have the newer software working properly.

  • Leonel1805's avatar
    Leonel1805
    Copper Contributor
    Sep 20, 2026

    Hi,

    Summary:

    "Many users face this issue due to current limitations with IMAP support and authentication.

    Unfortunately, new Outlook Requires Microsoft Cloud Sync for IMAP:

    Unlike Classic Outlook, New Outlook forces all IMAP accounts to sync through Microsoft’s cloud."

    Take a look in this post: 

    https://learn.microsoft.com/pt-br/answers/questions/5521775/n-o-consigo-cadastrar-minha-conta-uol-no-novo-outl?from=ContactUsWebBCQR&CorrelationId=14059bc0-35f2-45a9-a91e-4778f97f0d4b