I'd like to share our family email across all the machines on the home LAN. I know just using Gmail or something would probably be easiest, but I like a challenge and wanted to try to filter out junk and virus scan.

Here's my plan:
1) install dovecot (and later probably spamassasin) on my debian machine
2) create a common user like "familymail"
3) use fetchmail (or getmail) to download the mail from our ISP periodically
4) each user can then use their email client to check our family email

Now, I tried this once before and it worked well for the windows XP clients and clients on other networked machines. But I had trouble with the linux clients on the debian machine (dovecot server machine) because the shared user directory didn't have the correct permissions for other users. I thought if I used the debian machine LAN IP (instead of localhost) it would fix the problem, but I was never able to remedy the situation and hosed up the permissions on the "familymail" user directories.

Any advice would be appreciated.