I Have a similar problem as:
mystery solved: unclean shutdown causes redo.log to be owned by root:root
I have used zmfixperms but it does not seem to have fixed it. I run Zimbra on Mandriva:
The problem occured after a power off and running fsck on the drive that holds zimbra.
For some users they get the following message when trying to send using the web GUI.
msg - system failure: indexMessage caught IOException
code - service.FAILURE
method - ZmCsfeCommand.prototype.invoke
detail - soap:Receiver