Backup of databases or mailboxes or browsing of mailboxes fails with "MAPI IMsgstore has not been retrieved from IMAPIsession. HRESULT: -2147221219". To fix this issue, install the MS update rollup.
While restoring mailbox items using option "Do not overwrite existing items" fails, when all restored items exist. Select another items or select option "Overwrite existing items" to solve the issue
If you attempt a mailbox backup including hidden mailbox, you receive an error. Unhide the mailbox in order to perform a mailbox backup
How can individual FTP users access MassTransit mailboxes via URL?
In order to access FTP-published mailboxes via URL, the username and password for that individual must be specified. If no username or password is provided in the URL, the FTP client will attempt to connect to the FTP resource anonymously. The username and password may be provided in the URL via the following method:
Make sure the correct user accounts with the required permissions are used
Download and install the fix
Mailbox level recovery of a non-existing linked mailbox fails with "PowerShell error details: The user account for a user mailbox must be enabled"
Mailbox backup fails with error "Cannot open public folder or mailbox '<mailbox>'".
How to troubleshoot issues with mailbox backup
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.