[exim] File Lock

Hi all,

Occasionally, I get a file locking error.

defer (-9): failed to lock mailbox /var/spool/virtual/xxxx.ca/lib
(fcntl/flock)

An messages sit in the queue and eventually fail.

Is there some way to recover? Is this an exim error or FreeBSD error.

I have tried to delete the mailbox, and restart exim etc etc.

-Grant