Accessing your mail server across an SSL connection will give you the same security as through your VPN.
However, I add my private LAN IP of my mail server to the HOSTS file of my branch offices and laptops. The VPN client on the laptops are set to auto connect when the PC tries to access any IP's that exists on my private home office LAN. So when they access the mail server it gets the IP from the hosts file which in turn automatically makes a VPN connection to the home office. You could set the VPN client to manually connect and make the VPN connection first, but that seemed to confuse some users. |