As my wife now has two offices it was necessary to tie them together. I think I have spoken out this in previous posts. Previously I have spoke about getting WebDAV working on her server and the problems encountered with Windows 7. Now to get e-mail working.
My ISP, a strangly named, Big Wet Fish, offers me webmail using a very light and simple UI named squirrelmail. Which anyone can download freely from squirrelmail.org. This product is also extremely easy to install using the supplied quick install instructions.
I followed these very closely. I already had Apache and PHP and a Dovecot IMAP server, so I simply substituted where necessary. I also setup Apache with a virtual server with SSL for external access.
SquirrelMail is so quick and light that even over the slow connection on the server side (1Mbps upload and 3.5Mbps download) that its hardly noticable with the quickness of squirrelmail. Highly recommended.