Run TB in safe mode (hold Shift when you launch TB) and see if it makes any difference. Note also that when you click Get Messages, only the currently selected account is checked; click the drop-down to check a specific account or Get All New Messages (Shift+F5). The setting isn't present for folders that are automatically checked, such as Inbox. See the attached picture for the Properties window for a user-created folder. If these methods do not work, then contact the support team of your email provider. So, here are the solutions you solve the problem of the IMAP folder not syncing.

Why IMAP Folder is Not Properly Syncing?

Please report suspicious activity using the "Report Abuse" option. Windows 10 will reach EOS (end of support) flush DNS and re-sync Outlook on October 14, 2025. For more information, see this article.

Chosen Solution

Suspect some Apple Dev's have been lazy with some code mailbox not updating on IMAP in IOS18's mail.app and its causing the issue. I was a little hesitant but went ahead and let it completely remove all the synced items from the account off of my iPhone. After a minute, it was removed so just went and re-added it and BOOM. Decided to just try completely removing my Gmail account, the one that wasn’t syncing with the Mail App after the iOS 18 update.

IMAP folder sync issue in the new Outlook (moved emails not syncing to webmail)

If the server is down and you are experiencing issues, the problem IMAP folder is not syncing occurs. So, check the status of your IMAP server follow the steps below. These a general steps to check your IMAP settings in any email application. With the help of this, you can also ensure that the server settings are properly configured or not.

• If you can, turn off IMAP, require 2FA, and use the native outlook client.
• Their webmail works fine, and when this account is added to the Windows Mail app, everything works perfectly.
• I also noticed that some IMAP settings — like the root folder path (e.g. "INBOX") — are not available in the new Outlook, which makes troubleshooting more difficult.
• I would suggest that frequent changes to folder contents on multiple devices will make it go wrong.
• I’ve never heard of setting a path before for email, so apologies if this is a simple solution to those who come across this in the future.
• Simply enter your email address OR username in order to reset your password.

My accounts in Mail app stopped to sync post update

Simply making a change in Outlook does not in and of itself mean that anything has changed in Gmail. For example, you can disconnect from the Internet and make changes. Outlook needs to explicitly reach out to Gmail and communicate mailbox not updating on IMAP the changes you've made. I would suggest that frequent changes to folder contents on multiple devices will make it go wrong. Stack Exchange network consists of 183 QA communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. This anomaly also occurs when using the hosting system (first type), using different names for inbound and outbound servers.





Mohit is a Microsoft Certified expert for all things Microsoft. He brings a unique perspective gained from nearly a decade of active participation in various IT forums, blogs, and social media. Through this hands-on experience, he has acquired knowledge in diverse domains like Microsoft 365 Cloud, On-Premise Exchange Server, AD, and Entra ID. At first, I was thinking it may be an issue with certificates, but it's not... I went to a bunch of online TLS tests and the mail server is fine and the certificates are trusted...