Hi,
since my Sony Z5 Compact (Android 6.01) does not work any longer, I temporarily switched to a Sony Xperia E1 which runs Android 4.4.2.
I have a Aqua Mail backup from 10th Dec which I tried to restore from OneDrive as well as from local folder, but neither the cloud backup nor the local file could be recognized by Aqua Mail (OneDrive browser window did not show the file, local search told me "No backup found" - and I can ensure that I opened the correct path

).
I thought if this might be due to different Android versions - but then I tried the following:
- renaming my old backup file from AquaMail.accounts.backup to AquaMail.accounts1.backup
- create a new backup after manual set up of one of my email accounts (now Aqua Mail recognizes the new file and I could immediately restore it from the backup screen)
- keeping the backup screen open and switching to the file explorer
- in the explorer I deleted the new backup and re-renamed the old backup so that it had the same name as the new (deleted) one (AquaMail.accounts.backup)
- with the Aqua Mail backup screen still open the Restore button was still active - so I clicked ...
- and the recovery of my previously not recognized backup worked
Last year I switched from Z3 Compact to Z5 Compact and iirc the recovery was possible at this time.
I will get a Sony XZ the next days which runs Android 7 - I wonder how it works on this device.