SquirrelMail on OSX Client

Download Squirrelmail (1.4.5)

Move the downloaded folder to "/usr/share" and rename it "squirrelmail"

Copy these 4 lines to your apache config file at /private/etc/httpd/httpd.conf

Alias /WebMail /usr/share/squirrelmail
Alias /webmail /usr/share/squirrelmail

<Directory /usr/share/squirrelmail>
Options Indexes FollowSymLinks
</Directory>

Proceed via terminal:

sudo apachectl graceful

cd /usr/share/squirrelmail

chown -R www data
chgrp -R www data

mkdir attachments

chown -R root attachments
chgrp -R www attachments
chmod -R 730 attachments

/usr/share/squirrelmail/config/conf.pl

Select "D. Set pre-defined settings for specific IMAP servers"
Type "courier" after the "Command >> " prompt
Save the new settings in the exit process and that takes care of webmail capabilities.
Just point your browser http://yourdomain.com/webmail.