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Outlook Error - Cannot Connect to Server

Melissa Bailey 20 Reputation points
2026-04-06T11:01:05.1233333+00:00

I have four IMAP email accounts that I access through the Outlook Desktop version. These email accounts are set up identically on three different devices; two Windows 11 computers and an Android cell phone. Outlook is working fine on one Windows computer and on my phone, but on the other computer, I suddenly started getting the message that Outlook cannot connect to any of the four servers to obtain my mail.

The only difference on the computer where Outlook is no longer working is an Office update I performed last week, but Outlook was working fine for several days, so I don't have a clue what happened.

I've tried the online and quick repairs, but still get the same message.

I've also tried repairing the individual accounts in Outlook, but that fails, too. The test message error message says it cannot establish a secure connection, then below it is says "Your server does not support the connection encryption type you have specified. Try changing encryption method." then tells me to contact my mail server administrator (that's me) or the ISP. ??? I haven't changed anything, and if I had changed something in my MS admin account, it would affect at least my other Windows device if not the Android device, too.

I've even tried turning off my Firewall and other security software, but that doesn't make any difference, either.

This morning when I open Outlook on the affected device, I have a banner message at the top that says "Privacy Settings Applied: Your account privacy settings are being applied to this device. To adjust your settings, go to privacy settings." The link to get more information doesn't work and I haven't changed any privacy settings on my account.

How do I fix this?

Outlook | Windows | Classic Outlook for Windows | For business
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  1. Jayden-P 18,565 Reputation points Microsoft External Staff Moderator
    2026-04-06T11:52:01.3866667+00:00

    Hi @Melissa Bailey

    To assist you better, I will need more information.

    • What is your IMAP provider?
    • Please provide the Outlook version you are using on both Windows devices.
    • Please also provide what license/subscription you are using for Outlook. (Outlook 365, Home and Business 2016, 2019, etc.)

    Meanwhile, have you tried clearing your old credentials in Credential Manager in Windows - Microsoft Support?

    If the issue persists, try rebuilding .ost file: Close Outlook > Press Windows + R > Type in %LOCALAPPDATA%\Microsoft\Outlook\ > Look for your email address and delete it > Restart Outlook.

    I look forward for your reply.

    Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

  2. Q&A Assist
    2026-04-06T11:01:28.2433333+00:00
    AI generated content. This question contains an answer created with AI from Q&A Assist. Learn more

    Based on the symptoms (IMAP accounts suddenly failing to connect securely on one Windows device, while working on others, after recent updates), the issue aligns with known Outlook IMAP/POP connection problems and profile/connectivity issues. Use the following steps on the affected Windows computer:

    1. Regenerate and update app passwords (if the IMAP providers use them) If any of the IMAP accounts use app passwords (common with providers that enforce modern auth or 2FA):
      1. Sign in to each IMAP provider’s webmail.
      2. Go to Account Information > Security (or equivalent) and create a new App Password for Outlook.
      3. In Outlook on the affected PC:
        • Select File.
        • Under Account Information, choose each IMAP account.
        • Select Account Settings > Server Settings.
        • Paste the new app password into the Password box.
        • Select Next, then Done.
    2. Check for TLS 1.3 issues on Windows 10 (skip if the affected device is Windows 11) If the affected machine is actually Windows 10 (or was upgraded and inherited TLS 1.3 settings), TLS 1.3 can cause IMAP/POP connection failures:
      1. Open Regedit (Start > type regedit > Enter).
      2. Navigate to: Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols
      3. Look for a TLS 1.3 key under Protocols.
        • If present, right‑click Protocols and Export to back up the key.
        • Delete the TLS 1.3 key and its subkeys.
      4. Restart Outlook; if still not syncing, restart Windows.
    3. Repair the Outlook profile on the affected device Since online and quick Office repairs did not help, repair the Outlook mail profile itself:
      1. In Outlook, choose File.
      2. Select Account Settings > Account Settings.
      3. On the Email tab, select the profile/account and choose Repair.
      4. Follow the wizard and then restart Outlook.
    4. Run the Outlook connectivity troubleshooter If the profile repair does not resolve the issue:
      1. On the affected Windows 10/11 PC, run the classic Outlook for Windows connectivity troubleshooter from the Start button in the article (aka.ms/SaRA-OutlookDisconnect).
      2. When prompted, allow Get Help to open and follow the steps. This tool can detect profile, network, and authentication issues specific to that device.
    5. If using Outlook.com IMAP in multiple clients If any of the four accounts are Outlook.com accounts configured as IMAP in multiple clients, Outlook.com can block IMAP sessions:
      1. Go to account.live.com/activity in a browser.
      2. Under Recent activity, find the event matching the time of the connection error.
      3. Expand it and select This was me.
      4. Try connecting again from Outlook on the affected PC.

    If, after these steps, the affected PC still cannot connect while the others continue to work, keep Outlook fully updated and monitor for fixes, as similar IMAP and connectivity issues have been identified as product issues in some cases.

    References:

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