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Exchange error -3420 (unknown)

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I'm backing up our Exchange 5.5 server using Retrospect 6.5.350, and the retrospect agent. I can backup files and folders, the information store, etc all properely. I can also backup the majority of mailboxes without a problem. However, I'm getting between 7-12 errors (In 4 backups, the errors were all in that range) per backup. The errors are all "can't read, error -3420 (unknown)", and they all seem to relate to individual files in the users' mailboxes. This doesn't happen to all users, I'm backing up around 35 mailboxes and only 5 or so have errors.


Any ideas what could be causing this? I've got the users to exit out of Outlook before leaving on friday, but the errors are still occuring.


I've copied and pasted one below, they're all similiar, with the file path the only thing that changes:



File "Jason Sidney\Inbox\000000006dce17c930a8764a920e39d65e8c643107007241626ca67cfb47b48e8fe4a5a41a1500000049ea3b0000cc5533cb11724242a8f39fd1808d13af0000000095110000": can't read, error -3420 (unknown)


Thanks in advance,


Andrew smile.gif

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It could be corruption in the mailbox. As a test export a problem mailbox to a PST file and then import the PST file under a different user account and try to back it up. If the backup runs successfully chances are there is a problem in the mailbox structure somwhere.




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