This has been submitted as a ticket (30F-25AF15BA-0006), but ST have asked me to post in the Community too.

After upgrading to Beta 7314 one user has reported that all of thier folders within Outlook for Mac (latest version and connecting with EWS) are empty. New emails are being received, but the majority of their historical emails have vanished!

Everyhting is still available via webmail.

We have tried removing the account from Outlook, deleting the connection via webmail and re-adding the account, but that didn't work.

We've also tried setting up new Outlook profiles and also create the new profile and account on a different user's local account on the Mac... still no luck.