I've read wiki entries and some forum posts about blobs without meta data, and meta data referring to non-existent blobs, but I'm still a bit confused as to what leads to this situation.

We currently only have a few mailboxes on our zimbra setup, and today my own mailbox responded with an error:
"msg: no such blob: mailbox=x, item=yyyy, change=zzzzz"

After running zmblobchk:

* MailboxGroup=x, mailbox=x, item=yyyy: file not found: yyyy-zzzz.msg (delete associated metadata)
* /opt/zimbra/store/0/5/msg/0/1541-5728.msg: no associated metadata (delete blob)
* /opt/zimbra/store/0/5/msg/0/1549-5755.msg: no associated metadata (delete blob)
* /opt/zimbra/store/0/5/msg/0/1546-5748.msg: no associated metadata (delete blob)
* /opt/zimbra/store/0/5/msg/0/1561-5801.msg: no associated metadata (delete blob)
* /opt/zimbra/store/0/5/msg/0/1562-5809.msg: no associated metadata (delete blob)
* /opt/zimbra/store/0/5/msg/0/1548-5754.msg: no associated metadata (delete blob)

I checked in the database to look at the metadata, and the subject, etc. is for a mail I have not popped, I also grepped for it in /opz/zimbra/store and found nothing. I was kind of hoping that I had popped the mail, and the metadata had stayed behind, and no mail was lost, but it would appear that it has been lost.

How common is this, and what could be the cause? Would the converse situation also highlighted above (blob on storage without metadata) also lead to lost mail, since the customer will never even know about that mail, and it can't be popped because there's nothing in the database pointing to it? Is there a way to generate metadata for it?

In order to restore my mailbox to a functional state I had to delete the item's entry.

Regards,
Eric Kruse