Make Outbound PPTP Connections from Behind a Firebox
If necessary, you can make a PPTP connection to a Firebox from behind a different Firebox. For example, one of your remote users goes to a customer office that has a Firebox. The user can connect to your network with a PPTP connection. For the local Firebox to correctly allow the outgoing PPTP connection, add the PPTP policy and allow traffic from the network the user is on to the Any-External alias.
To add a policy, see Add Policies to Your Configuration.