Problem description
The backup for the user completes successfully but the backed-up folders are empty.
Cause
This error indicates Microsoft Exchange is preventing data backup for the user due to a quota/limit being exceeded. For example: If the mailbox has a limit of 10 GB of storage but has exceeded this limit, Microsoft Exchange may prevent a backup from that mailbox until the mailbox is within the allowed quota. Microsoft Exchange Online has multiple limits which may prevent you from sending an email.
Refer for more: Exchange Online Limits
Traceback
📝 Note
[ERROR] Could not list MAPI folder InboxAQMkAGRhNmJiAGViOS1hZTlkLTQ1M2QtYWRmOS03OTkBZThlYjQyNzkALgAAA1PuA5wAFNFCvLm9jLeb6O0BAJeA1BnmiiFGkFS8M4-BU6wAAAIBDAAAAA==. Cloudapp Skipping. type:MAPI Email Error:Unable to read file. Permission Denied Response Code: 403 Text:{"error":{"code":"ErrorQuotaExceeded","message":"The process failed to get the correct properties."}} (#100000046) User user@contoso.com.
Resolution
Verify you can send email from the mailbox directly in Outlook or Outlook Web Access (OWA). If you cannot send email from Outlook and you have verified the mailbox has not exceeded any quotas, contact your Exchange administrator or Microsoft Exchange support.