I'm no technical moron but I'm not familiar with Veeam and I'm obviously being extremely cautious when touching mailboxes with decades worth of history.
I purchased 30 licenses and set it up with the defaults. I backed up a few mailboxes and it was painless and I checked the backups and they look great.
Prior to each one I made a backup of each users' OST file because of my paranoia something could happen and wipe it out in the process.
Is there anything that could cause that with Veeam Backup for Microsoft Office 365? Hoping you can calm my nerves...