Offline archive - out of space 365 mailbox
This cannot be done without extra lengthy steps; options:
1. increasing email storage / archive - beyond 50 GB mailbox / 50GB Archive requires either an extra Exchange P2 license for that mailbox or an E3 license
2. Download as a PST, autoarchive old data, re upload to cloud or manage to cache the entire mailbox and work on in locally (didn't work a few times)
Resolution:
1. Created a backup pst of the entire manager mailbox and copied it to the server under outlook files
2. Created a stand-alone profile of just the manager account, set caching to the maximum and the entire mailbox did manage to download (didn't work with all the other files loaded)
3. Auto-archived anything older than one year and run a manual sync with 365
4. The cleaned mailbox now has 15Gigs free
5. Since there isn't allot of free space - set an autoarchive rule every 14 days of anything older than 1 year to an archive file on the server (u:\documents\outlook files\)