I am setting up Exim on a Debian box. The box is connected to the internet through a consumer DSL line with a dynamic IP address, so not suitable for sending messages directly.
For privacy reasons I would like to avoid using a third party SMTP relay, or running my own relay in another location (e.g. virtual server). So I would like to configure Exim to send mail through an SSH tunnel to my virtual server (also running Debian).
I see there are instructions at the Debian wiki for sending through an SSH tunnel to a smarthost, but I would like Exim to make the SMTP connections to the recipient mail server directly through the tunnel. I guess this could either work through dynamic port forwarding (SOCKS proxy) through a 'persistent' SSH connection, or by establishing a new tunnel for each connection to a recipient mail server.
I have tried Johannes Franken's example Exim configuration which seems to address a similar use case, but when I restart Exim with the new configuration I get the error
option "bsmtp" unknown. I'm also not sure whether this approach requires an SMTP relay to be running on the remote server.