alias /webmail

[victor531]

When you change your default port it works like this http://www.virtualdomain.tld/webmail then it is redirected to the webmail with the correct path, This works only for the domains who where created after the port was changed.
At least it works for me, just try.
This is the Howto for changing the port
http://www.isp-control.net/ispcp/wiki/howto_defaultport

Victor