OpenVPN tunnel whole interface

[dovad]

I have pfSense installed at home and my office.

home: dynamic ip
ports 25 & 80 blocked by ISP

office: static ip
no ports blocked

I would like to configure a site-to-site OpenVPN connection with the server on the office router and the client on the home router.
I have a spare Ethernet Interface on the home router which I would like all internet traffic on that interface to be tunneled through the office router. I would like to connect a switch to that spare home interface and plug in an email server and a web server so they can use port 25 & 80 through the OpenVPN tunnel and the office connection.

I have a handle on setting up site-to-site OpenVPN connections and have several tunnels working connecting different offices but I am uncertain of how I need to configure the home side to get the desired connections that I want. I'd also appreciate pointers on how to set firewall rules at the office to direct port 25 & 80 across the tunnel to the home nodes.

Help is very much appreciated.

Thank you!