
It also provides the option to export the Outlook OST file into Office 365 and Live Exchange
mailbox not updating on IMAP mailboxes. This software also has a splitter option to split large-sized PST files into smaller ones, helping users prevent oversized PST file issues. With directory synchronization, you can continue to manage users and groups on-premises and synchronize additions, deletions, and changes to the cloud. But setup is a little complicated and it can sometimes be difficult to identify the source of problems. We have resources to help you identify potential issues and fix them. Incorrect Outlook settings can also be one of the reasons behind Outlook synchronization errors.
Method 4: Recreating the Outlook Profile

Another which is shown below, is a user opens a new message, or replies to one, and lets it sit for a while. When they go back to the message and press send they get an error that the message has been deleted. Ive repaired the OST and changed cache
Office 365 Sync Errors Fix mode to only cache 1 year.

Check the connectivity to your email server
- The client has a computer off the domain at home that his work email is tied to and he has never had any of these issues in Cache mode with that device.
- When the user is signed into their mobile app, webmail, or the Windows Mail app, they are able to receive email perfectly fine with those.
- An app password is used instead of your normal account password for apps that don't support two-factor authentication.
- Once the client started using Outlook again after some time has passed the issue had come back.
- If it does, you might need to include Outlook exceptions in the settings of your security program.
- When they go back to the message and press send they get an error that the message has been deleted.
- The other solution to fix Outlook sync issues is recreating Microsoft Outlook profile.
When the user is signed into their mobile app, webmail, or the
FixTechGuide support for Office 365 Windows Mail app, they are able to receive email perfectly fine with those. The issue is occurring only in the Outlook program installed on Windows. To update from Azure AD Sync to Microsoft Entra Connect, see the upgrade instructions.
Methods to fix Microsoft Outlook syncing error
I ran the PSTscan tool to check for anomalies on the OST file (which it found and repaired but the issue still occurs). However, with one particular client no matter what changes are made these sync issue still occur. We're sorry you're having problems with the Mail and Calendar apps for Windows 10. To fix the issue, please try each of the following solutions in order.
Microsoft Outlook Sync issues
I’ve tried the Microsoft office uninstall tool provided by Microsoft (which deletes more items then just control panel uninstall). Below are the steps I’ve taken to try to resolve this issue. Two-factor authentication helps protect your account by making it more difficult for someone else to sign in. It verifies your identity using your password and a contact method (also known as security info). Outlook will show as connected to Exchange but is not receiving any new email. This can happen for days at a time, and then disappear for a day or 2, only to appear again.