outlook will not synchronize folders

Question

Task 'Synchronizing subscribed folders for ******@yahoo.ca.' reported error (0x800CCC0E) : 'Outlook cannot synchronize subscribed folders for ******@yahoo.ca. Error: Cannot connect to the server. If you continue to receive this message, contact your server administrator or Internet service provider (ISP).'

Answer 1

Hello

Many users seem to have this issue recently. Microsoft is still investigating this issue. The current workaround is published here: https://support.microsoft.com/office/users-get-errors-0x800ccc0e-0x800ccc0f-synchronizing-gmail-and-yahoo-accounts-in-classic-outlook-e5a7b684-7c5c-4848-ab2d-d48291451f67

Answer 2

For a Yahoo IMAP account in Outlook on Windows that fails with 0x800CCC0E and cannot synchronize subscribed folders, use the following approaches that are supported in the provided context.

1. If using Outlook for Mac with Yahoo IMAP

For Yahoo accounts configured as IMAP on Outlook for Mac, there is a known issue where folder content does not sync correctly and messages can disappear and reappear. The documented workaround is:

1. Open Outlook for Mac.
2. Turn on the New Outlook switch to switch from the classic to the new Outlook experience.

This resolves known re‑syncing issues for Yahoo IMAP accounts on Mac.

2. If the issue is related to general IMAP/POP sync failures

For IMAP/POP accounts where the server connection is interrupted and sync fails, one documented cause is TLS 1.3 on Windows. The supported remediation is:

1. Open the Registry Editor and navigate to the Protocols key under the TLS configuration (as described in the article).
2. If TLS 1.3 appears under Protocols, export that key first (backup) and then delete the TLS 1.3 key and its subkeys.
3. Restart Outlook.
4. If sync still does not work, restart Windows and test again.

After this change, the registry should no longer show any TLS 1.3 keys under Protocols, which can resolve certain IMAP/POP connection interruptions.

If the problem persists after these steps, use the Outlook community and support options in the references to get case‑specific assistance.

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References:

• IMAP Yahoo and AOL accounts might experience issues with re-syncing folder content
• Outlook IMAP or POP server unexpectedly terminated the connection, and the server was interrupted
• Outlook.com contact folders not syncing