After sync the batches still showing Investigateing after 12 hours

Dear Simran Priya,

I understand that your IMAP migration batch has remained in the "Investigating" status for more than 12 hours, and that multiple Sync, Stop, and Resume attempts have not resolved the issue.

As an initial step, please try the following:

1. Verify the migration endpoint configuration and ensure the Maximum Concurrent Migrations value is set appropriately for your environment.
2. Review the status of the affected migration users to check for any synchronization or authentication errors.
3. Confirm that the source IMAP server is accessible and is not enforcing connection throttling or concurrent connection limits.
4. Creating a new IMAP migration endpoint and testing with a small migration batch containing one or two mailboxes.

Next, please refer to the guidance in My migration is slow (if issue not resolved). This article recommends reviewing IMAP server connection limits, firewall restrictions, and migration endpoint settings, as these can significantly impact migration performance and cause migration batches to remain in a syncing or investigating state for an extended period. It also includes guidance on increasing the maximum concurrent migrations and checking for source server throttling.

If the issue persists after completing the troubleshooting steps in the article, I would recommend creating a support ticket with the Microsoft Support team for further investigation, as additional diagnostics may be required to determine whether the issue is related to the source IMAP environment, migration configuration, or the migration service itself.

You can raise support ticket from:  https://admin.microsoft.com/Adminportal/Home?#/support/requests

For reference: Get support for Microsoft 365 for business

I hope your issue will be successfully resolved soon. If you have any further questions or need assistance, please do not hesitate to contact me.

Wishing you a wonderful day ahead.