LK Hill: I have the same question; adding on to your query.
Sherry:
I use Microsoft Outlook for Mac v16.84.2 (24042814) with a 365 subscription.
It is not clear how the data in New Outlook is being handled. I don't see anything at all in the folders named "On My Computer". Plus all my New Outlook folders show inconsistent email counts while hovering on individual folders and sub-folders. I see an option for "sync" while right clicking on each folder; awaiting results if I get access to all my 15 years of emails. I am sure there are people like me who rely on Outlook for a certain type of "file management" in addition to local filing folders by virtue of file attachments. Clubbed with sender info and time stamp, it becomes a more powerful resource than just filing of files in local folders.
In New Outlook, I don't see any option to Export, this is scary. What's the best way to export for backup purposes. MacOS Time Machine is not an ideal solution but that is a separate discussion.
Is the migration file an exact duplicate that can be ignored and deleted? (Not even sure where the migration files are in the first place). But like I said, I don't see anything in "On My Computer" folder.
Thanks,
PK