I have been seeing this in an email sent to the zimbra account on the MTA server box. We are in a multi box configuration 1 MTA and 1 LDAP+MailStore. We are currently on 4.5.4 but I have planned to upgrade to 4.5.10 tonight. When I look in the Backups tab for admin it looks like I have been getting backups properly.

Any idea what this is?

This is ONLY occurring on the MTA I see no mention of it on the other server.