If you want to login directly to your favorite webamail you can do the following:

1) Login in to your cPanel interface.
2) Create sub-domain, i.e webmail.domain.com (replace domain.com with your actual domain name)

Your sub-domain folder path should be public_html/webmail

3) Create .htaccess file in the document root of sub-domain public_html/webmail

Add the following rewrite rules to .htaccess

For RoundCube

RewriteEngine on
RewriteCond %{HTTP_HOST} ^webmail.domain.com$ [OR]
RewriteCond %{HTTP_HOST} ^www.webmail.domain.com$
RewriteRule ^(.*)$ http://domain.com:2095/3rdparty/roundcube/$1 [R=301,L]

For Squirrel Mail:

RewriteEngine on
RewriteCond %{HTTP_HOST} ^webmail.domain.com$ [OR]
RewriteCond %{HTTP_HOST} ^www.webmail.domain.com$
RewriteRule ^(.*)$ http://domain.com:2095/3rdparty/squirrelmail/$1 [R=301,L]

For Horde:

RewriteEngine on
RewriteCond %{HTTP_HOST} ^webmail.domain.com$ [OR]
RewriteCond %{HTTP_HOST} ^www.webmail.domain.com$
RewriteRule ^(.*)$ http://domain.com:2095/horde/$1 [R=301,L]

Replace domain.com with your actual domain name.

Now access http://webmail.domain.com it should redirect to your favorite email