For a long while, I've been running IMAP on my Linux machine. This provides the ability to use different front ends to get to my mail. In order to move this to my server machine which is on 24x7, I created a dedicated Solaris Zone ("mailserver") which I've then installed Courier IMAP. A quick test with Thunderbird on my Linux install proved this was working.
To configure for the Mac:
Mail.app had a problem with the sorting of mail folders. The folders below Inbox were shown separately under a "Mailserver" section and not as subfolders of the Inbox. The solution was to edit the account and remove the IMAP Path Prefix "INBOX" and replace it with nothing. This is contrary to what I've read on a number of other blogs, but works here. YMMV.
The final thing to do then is to select the IMAP folders for Junk, Sent and Trash and select Mailbox > Use This Mailbox For menus to designate how Mail.app should handle these types of mails.
Which now means I can access my mailstore from the Mac.