Intermittent mailbox not found

[Rob Mueller]

> I have inherited a cyrus / postfix server, which is generally 
> well-behaved.
> However, there is an intermittent error when delivering messages to a 
> certain
> mailbox.  It is infrequent, and generally the message is delievered on the
> user's next attempt in his MUA.  The log is something like:

What version of cyrus and what version of postfix?

Can you should the logs for a successful delivery to that account.

Rob