Subject:   -54- Why do mail programs have trouble with NFS-mounted
                mailboxes in IRIX 5.3?
Date: 23 Sep 1995 00:00:01 EST

  It's a bug, fixed by patch 547 (and its predecessors 216, 401 and
  481).  If the client and server are both IRIX 5.3, you can also work
  around the problem by changing the mount type to NFS3. (See notes on
  NFS3 elsewhere in this FAQ.) Typical symptoms include "Warning: could
  not lock /var/mail/user after 100 trys." (from /usr/sbin/Mail) and the
  presence of user.lock and user.rolock files in /var/mail. See also
  "NFS Mounting Mail with IRIX 5.3 and IRIX 6.0.1" in the Sep/Oct 1995
  Pipeline.