[exim] Exim and NFS mounted mail spool

Hi folks,

We have a mail server (Mail1) with 3373 mbox mail accounts,
in /var/spool/mail. I am setting up a second mail server (Mail2)and am
mounting /var/spool/mail & /home from Mail1 on Mail2 via NFS.

If delivery of mail on Mail2 is configured to a non-NFS directory, delivery
is lickety-split. However delivery to the NFS mounted mail spool is greatly
delayed, with frequent time-outs.

In this setup, is it that the mail spool is mbox rather than maildir likely
the source of the lack of Mail2's performance?

--
Cheers,
Rob