I am also not a security expert. But you seem to be correct in both cases. The spiped website also has an example of encrypting SMTP traffic between two servers

I am also not a security expert. But you seem to be correct in both cases. The spiped website also has an example of encrypting SMTP traffic between two servers in an spiped condom. https://www.tarsnap.com/spiped.html https://www.tarsnap.com/spiped.html