/mail alias continues to work even after removed from apache VH

==== Required information ====
- iRedMail version: .08.6
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): ldap
- Linux/BSD distribution name and version: deb7
- Related log if you're reporting an issue:
====

Hi Zhang,

I'm just curious.. I have a site, http://www.domain.com

I have removed /mail as Alias to roundcubemail in the virtualhost and restarted the server. Yet, after refresh, cache clear, and even on new machine - http://www.domain.com/mail still works! I've never seen anything like it! Any idea?