mDaemon to 365 migration issues

Have a client who is migrating their email to Microsoft 365 from an onsite mDaemon server. When trying to do an IMAP migration to 365 I see the initial connection made when entering the server information in the logs but never see any connections made once the migration is initiated (in the mail.log). Migration fails with an internal server error (typically vague microsoft error). Not sure what I’m doing wrong and I don’t want to drop several hundred dollars to buy a program that supposedly makes it easier. There are only 11 accounts so if I have to I can import the pst files. Just wanted to know if anybody has experienced this before or had suggestions. First time for me doing anything in 365.

The error message would actually be helpful even though it may seem vague. Typically the issues with imap migration are either offie365 is not able to connect to the server, there is an issue with the csv file, or you either forgot to create a user in office 365.

I found my way into the exchange admin portal (I was working from the 365 Admin center). Created a new batch with my spreadsheet. Error indicates that there is already a sync process active for that user. I had already deleted all the other old batches that were listed. I can get more specifics later as I am remote at the moment.

Here is the error. Same for every user in the csv file. There are no other batches.

Error: UserAlreadyBeingMigratedException: The user ‎’‎’ already has a pending request. Please remove the existing request and resume the current batch or start a new batch for this user. --> Name must be unique per owning mailbox. There‎’s already a request with the name ‎’‎’ owned by mailbox ‎’CANPR01A007.PROD.OUTLOOK.COM/Microsoft Exchange Hosted Organizations/‎’.

Managed to get this issue figured out. Had to use powershell and the EXO module (install-module -name ExchangeOnlineManagement) to kill background syncs (remove-syncrequest) that had failed for each user. Now just dealing with what looks like connection issues to the mDaemon server.