Apache 2.4 : Rewrite to keep the original URL

["Fabio S. Schmidt" <fabio@xxxxxxxxxxxxxx>]

Hi,

I'm trying to setup an environment with a frontend interface which login and redirects to my application. 

The scenario is: The user access with webmail.domain.com and the login page redirects to the application, running on the same host, but on port 81.

How could I keep the original URL? I mean, the browser should keep the "webmail.domain.com" as the address.

My Apache configuration: 

<VirtualHost *:443>

DocumentRoot "/var/www/html/login_domain"

DirectoryIndex index.html *.php

ServerName webmail.domain.com

SSLEngine on

SSLCertificateFile /etc/ssl/crt/apache.crt

SSLCertificateKeyFile /etc/ssl/crt/apache.key

        SSLCertificateChainFile /etc/ssl/crt/ca.crt

</VirtualHost>

<VirtualHost *:80>

DocumentRoot "/var/www/html/login_domain"

DirectoryIndex index.html *.php

ServerName  webmail.domain.com

</VirtualHost>

Kind regards.

Fabio S. Schmidt