wesley-sba
You need to login to the mailbox and manually remove the stuck email from the fetch folder. The system cannot process that email for some reason and since it can't be processed it can't be moved, etc. We've had many reports of people having issues with the Archive - Move to folder option and they've said that changing it to Do Nothing (not recommended) seems to fix the issue.
You can also keep everything the same and try the below patch. Just beware it has not been reviewed, tested, etc.
Cheers.