debian: mail spool directory ???

[Brendan J Simon <brendan.simon@ctam.com.au>]

What is the official mail spool directory ?
/var/spool/mail ?
/var/mail ?

I'm running a PowerMac G4 with exim.  Things were working fine till I
tried to install zmailer.  I had a few errors so I switched back to exim
for the time being.  I could no longer read my mail through an IMAP
client running on another machine nor through elm running on the same
machine as the server.

elm was looking for mail in /var/spool/mail but the mail was actually in
/var/mail.  I think there must have been a symbolic link from
/var/spool/mail to /var/mail.  I recreated the link and everything seems
fine.
Is this the correct setup ?
If so, why was the link removed in the exim to zmailer to exim
changeover ?

I assume there is an official Debian location for mail, where all mail
clients should look.

Thanks for any help,
Brendan Simon.