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TLRS-Sandwich's avatar
TLRS-Sandwich
Copper Contributor
Jul 30, 2026

Intermittent connection error with an IMAP mailbox

One of our customers is having an issue with new Outlook where after we set up their email as IMAP (which we host), after a while Outlook would no longer recognize the password. When they went into Settings, it showed a message says "Sign-in is required. Click Sign in to resolve." The customer did that, and the sign in failed, so they closed new Outlook and did something else for a while we investigated.

However, the user came back to the computer a little later, opened Outlook on a lark, and everything was back to normal and they could see all their email again.

Does anyone have any idea of what might be causing that? The customer forwarded screenshots of the information they got when they clicked "Troubleshooting Details", but I don't know how helpful that will be for y'all.

3 Replies

  • You're trying to determine why a hosted IMAP account in new Outlook stopped accepting its password, then recovered without credential changes. That recovery means the banner does not prove the password was wrong; check whether your server rejected authentication or Outlook could not connect.

     

    Confirm the username, IMAP host, port, encryption, and any app-password requirement. At the next occurrence, record the UTC time, preserve Troubleshooting Details, test webmail, and review the mailbox’s IMAP authentication logs for that timestamp. If webmail works and the server shows no rejected login, capture a new Outlook network trace or use Help > Get Diagnostics before restarting Outlook.

     

    If server logs reject authentication, correct the credential or app-password policy. If they show successful authentication, remove and re-add the account under Settings > Accounts > Your accounts, then give Microsoft Support the details, trace, and timestamp. Without those logs, the exact cause cannot be determined confidently.

    • TLRS-Sandwich's avatar
      TLRS-Sandwich
      Copper Contributor

      Thank you for the advice on how to perform troubleshooting. I'm not a traditionally-trained Level 1 support tech, so having that reminder was nice.

      I was more looking for a general answer regarding whether anyone else has noticed this issue with new Microsoft Outlook and IMAP email mailboxes. There are many issues that have been attributed to just "new Outlook being new Outlook" and I was wondering if this was just one more thing to add to the stack of them. I probably should have been a bit more clear that I was doing a temperature check of other users in the tech community than a specific solution for this customer.

    • TLRS-Sandwich's avatar
      TLRS-Sandwich
      Copper Contributor

      Thanks for this. I'll talk it over with my supervisor and if we have more questions, we'll follow up in this thread.