Alias /webmail /usr/share/roundcube
<Directory /usr/share/roundcube>
Options -Indexes
AllowOverride All
</Directory>
<Directory /usr/share/roundcube/config>
Order Deny,Allow
Deny from All
</Directory>
<Directory /usr/share/roundcube/temp>
Order Deny,Allow
Deny from All
</Directory>
<Directory /usr/share/roundcube/logs>
Order Deny,Allow
Deny from All
</Directory>