Comments on Routing and Allocation Policy Wanted

Alternatively, if you want to SMTP over email for a domain over the
dialup connection, assign the PPP client a primary MX record and a
fully connected server on the PPP server's network a secondary. The
PPP reconnect script on the client can be instrumented to flush the
outgoing queue and also send email to pseudo alias on the secondary
MX server that triggers a flush of its incoming queue for your domain.
You have to make sure you dialup at least once every three days or so.

This strategy requires the PPP client have a static IP.

No, it doesn't, or at least it won't after the dymamic DNS stuff is
finished.

Dave