Unable to generate Delta File, XXXX is being backed up in its entirety.


Exceeded the [In-File Delta] -> [Maximum no. of Delta] setting. File “S1\Microsoft Information Store\First Storage Group\Mailbox Database\Mailbox Database.edb” is being backed up in its entirety because more than 100 delta files have been generated already.


The software cannot generate the delta file, so it falls back to uploading the full file


  1. Check the amount of free disk space in the temporary spooling folder
  2. Wait until the backup completes, run another backup and see if the issue continues
  3. If it persists, wipe the temporary spooling folder and try again