I have a main domain.com and then an addon-domain.com. When I try to make gallery.addon-domain.com or webmail.addon-domain.com redirect to a directory such as http://addon-domain.com/webmail it only redirects me to the root of that website.

In other words, I want:

http://gallery.addon-domain.com --> http://addon-domain.com/gallery/
http://webmail.addon-domain.com --> http://addon-domain.com/webmail/

but instead it's doing:

http://gallery.addon-domain.com --> http://addon-domain.com/
http://webmail.addon-domain.com --> http://addon-domain.com/

Is this because it's an addon domain name?

Please open a ticket or post full domain names here. We need them to check.