I'm sure many of you have now figured out that webmail is not included in the current 5107R (version 6) of BlueOnyx.
If you want to install it, it is a fairly simple process:

1:Install the EPEL repository

SSH into your server and su to root.
install the EPEL repository with this command: rpm -Uvh http://bit.ly/q7kHBq
DO NOT RUN YUM UPDATE!!! doing so at this point will mess up your server!!

2:Install Squirrelmail

Install squirrelmail with these commands:
yum install squirrelmail.noarch
yum install squirrel-devel.i686.
Allow it to intall dependencies, but it is very important that you do not attempt to install anything else.
you should get an output something like this:
Resolving Dependencies
--> Running transaction check
---> Package squirrel-devel.i686 0:2.2.4-1.el6 will be installed
--> Processing Dependency: squirrel-libs = 2.2.4-1.el6 for package: squirrel-devel-2.2.4-1.el6.i686
--> Processing Dependency: libsquirrel-2.2.4.so for package: squirrel-devel-2.2.4-1.el6.i686
--> Processing Dependency: libsqstdlib-2.2.4.so for package: squirrel-devel-2.2.4-1.el6.i686
--> Running transaction check
---> Package squirrel-libs.i686 0:2.2.4-1.el6 will be installed
--> Finished Dependency Resolution

3: Remove the EPEL repository

Search for the RPM name with this: rpm -qa |grep -i epel
Remove the EPEL RPM with this: rpm -e epel-release-6-5.noarch
You may need to copy and paste the EPEL RPM name from the grep results.

4: Install the BlueOnyx addons

Use this command to install the remaining files:
yum install base-squirrelmail-capstone.noarch
Allow it to install dependencies. You should get an output something like this:
Setting up Install Process
Resolving Dependencies
--> Running transaction check
---> Package base-squirrelmail-capstone.noarch 0:1.0.0-0BX07.centos6 will be installed
--> Processing Dependency: base-squirrelmail-glue for package: base-squirrelmail-capstone-1.0.0-0BX07.centos6.noarch
--> Processing Dependency: base-squirrelmail-locale-ja for package: base-squirrelmail-capstone-1.0.0-0BX07.centos6.noarch
--> Processing Dependency: base-squirrelmail-locale for package: base-squirrelmail-capstone-1.0.0-0BX07.centos6.noarch
--> Processing Dependency: base-squirrelmail-ui for package: base-squirrelmail-capstone-1.0.0-0BX07.centos6.noarch
--> Running transaction check
---> Package base-squirrelmail-glue.noarch 0:1.0.0-0BX07.centos6 will be installed
---> Package base-squirrelmail-locale-ja.noarch 0:1.0.0-0BX07.centos6 will be installed
---> Package base-squirrelmail-ui.noarch 0:1.0.0-0BX07.centos6 will be installed
--> Finished Dependency Resolution

5: Reconstruct CCE and restart the Admin server

Reconstruct the CCE with this: /etc/init.d/cced.init restart
Restart the Admin Server with this: /etc/init.d/admserv restart
If all has gone well, you should now be able to access webmail with the following url:
http://www.domain.com/webmail

It is EXTREMELY important that you do not run yum update with the EPEL installed as it WILL damage your system.
Make sure the EPEL is removed BEFORE trying to update.

NOTE: The latest PHP update for blueonyx seems to break this install with the error:
Unknown: open_basedir restriction in effect. File(/usr/sausalito/configs/php/set_php_headers.php) is not within the allowed path(s)
To fix this, you need to add "/usr/sausalito/configs/php/" to the "php_admin_value open_basedir" values in /etc/httpd/conf.d/squirrelmail.conf.