Mailbox Backup Failure

Mailbox-level backup - is a type of backup that stores contents of Exchange mailboxes and/or public folders.

Acronis Backup accesses the contents using Messaging Application Programming Interface (MAPI), so backing up multiple mailboxes may take a long time.  Backing up at a mailbox level makes sense when you need to frequently back up a small number of mailboxes. Otherwise, consider a database-level backup (Information Store backup).

How to troubleshoot issues with mailbox backup

Introduction

A mailbox is a part of mailbox database that is a unit of granularity where mailboxes are created and stored. A mailbox database is stored as an Exchange database (.edb) file mostly on a separate mailbox server. A mailbox contains items like user's folders, calendar, meetings, attachments and etc.