backup a m365 mailbox with imapsync

The task was to backup a m365 mailbox with 50GB mailbox size.

The largest folder was the archive folder with a stately size of over 30GB.

After a long search I found imapsync.

In my case, this was the best option:

./imapsync \
 --folder Archiv --addheader --useuid --automap --logfile sync.log --maxsleep 10 \
 --host1 outlook.office365.com --user1 email@contoso.com --password1 YourHolyPa$$word1 --timeout1 48000 --delete1 \
 --host2 mybackupmailserver.com --user2 email@contoso.com --password2 YourHolyPa$$word2 --timeout2 48000

Sample output: