Symptoms:


Exchange 2007/2010 Mailbox Backups fail when Exchange is deployed where the Exchange roles are split among multiple servers.

You see something like the following in the Message Logs of the backup:
"MBXBackup Fatal: Failed to Configure Message Service. Networking error Check server name:MAIL : MAPI_E_NETWORK_ERROR"

Cause:

Microsoft's handling MAPI can make it so that our MAPI based backup is not possible when the Exchange roles are split in certain ways. It was discovered that other companies also relying on MAPI are running into similar problems.

The message level backups can be done but would require modifying your Exchange installation.

Test Results:

FAIL

Mailbox level backups will fail with the following or similar configurations:

  • Two or more servers with individual or split Exchange roles. For example, two servers, one running Client Access and Hub Transport, the other running the Mailbox server. Such a configuration will result in the following error at the time of backup:
    • MBXBackup Fatal: Failed to Configure Message Service. Networking error Check server name:MAIL : MAPI_E_NETWORK_ERROR

SUCCEED

Mailbox level backups will succeed with the following or similar configurations:

  • For example, two servers named Merrie and Arnie are on the same network.
    • Merrie had the Mailbox and Client Access roles installed.
      • Backups were successful for mailboxes on Merrie only.
    • Arnie had Mailbox, Client Access, and Hub Transport.
      • Backups were successful for mailboxes on both Merrie and Arnie
  • Mailbox level backups also succeed in the most common configuration for our customers: all of the Exchange roles on one single server.
  • Both roles are required on one server for the MAPI access mailbox level backups rely on to work (database level backups should still be possible).

Which servers should have agents installed on them to properly back up data?

The database backup must come from the server with the DB, and the mailbox from a server with the mailbox role and the client access role.
The same server does not have to do the database and mailbox backups.

For example, if there are two database servers, they both need the client that backs up the database. The mailbox client will need to be on any server that needs mailbox backups, and that server needs to have both mailbox and client access rolls.
What clients you need truly depends on how you decide to split the work between the servers.