I have a SBS 2003 with Exchange and have a problem with emails disappearing. I noticed the problem in Backup Exec, it gives me errors on certain email messages. In my log I see the error 12800 everytime BE tries to access these messages. I tried deleting the messages from the users mailboxes, but they don't seem to exist, or at least they are not visible in Outlook or OWA. I've read in different groups that this is a 'non-error' so I wasn't too concerned only now it's happening to new email. A user complained that someone sent her an email with an attachment and it never got to her. It was sent twice. I looked in message tracking in Exchange and the message is there and ends with 'message delivered locally to store to <username>' So in my logs it looks like it was delivered, but it isn't anywhere in her mailbox. Then in the server logs whenever that message was received I get the error 12800. I have tried putting the /3 gig switch in my boot.ini and that hasn't helped. I also don't get the 12800 message at all except when backup exec processes the mailboxes or when this one person tries to send this one word attachment. I will say that the sender mailed the attachment using eudora instead of exchange and it was received here just fine. Any ideas on where these messages may be? I've looked in Bad Mail and in Queues and nothing is sitting anywhere. Any and all help would be appreciated, Thanks, Amy

How big is the mail store? Did you try an offline defrag?

The store is a little under 3 gigs. Sorry, should have mentioned that I tried an offline defrag and it didn't help. I also did an integrity check and it says it's fine.