Give Apache permission to see Alias setting up in Global Vhost Entry

I would like to setup webmail acces using Global VHost Entry, for all the benefit that this provide. So I add
Alias /webmail /etc/sentora/panel/modules/Rainloop_webmail/app/ in Global VHost Entry (mudule admin/Apache config) and after that I restart apache service.
Then whe I try to get mydomain.com/webmail the answer is:

Quote: Wrote:Error 403 - Access Forbidden

You are not authorised to view this page or directory....
This may be due to the following reasons:-

1. The web server is setup to disable directory listings.
   
2. You supplied an incorrect user/password when attempting to browse this area.
   
   

If you believe you are getting this error message by mistake, please contact the website administrator.

Do you have any idea?

Thanks!