I understand that, so you mean to that the virtual host configuration should be like this?
<VirtualHost webmail.*:80>
ServerAdmin webmaster[at]domain.com
DocumentRoot "/etc/sentora/panel/etc/apps/webmail/"
ServerName webmail.domain.com
AddType application/x-httpd-php .php3 .php
<Directory /etc/sentora/panel/etc/apps/webmail/>
Options FollowSymLinks Indexes
AllowOverride All
Order Allow,Deny
Allow from all
</Directory>
<VirtualHost>
<VirtualHost webmail.*:80>
ServerAdmin webmaster[at]domain.com
DocumentRoot "/etc/sentora/panel/etc/apps/webmail/"
ServerName webmail.domain.com
AddType application/x-httpd-php .php3 .php
<Directory /etc/sentora/panel/etc/apps/webmail/>
Options FollowSymLinks Indexes
AllowOverride All
Order Allow,Deny
Allow from all
</Directory>
<VirtualHost>