mailr

dig txt starttls-everywhere.org ;; ANSWER SECTION: starttls-everywhere.org. 599 IN TXT "v=spf1 ip4:67.212.170.242 -all"

My server was dropping the connection after EHLO because they were connecting from a different IP address and specified -all in the SPF record. Maybe you are seeing a different issue.

I think there is an error in their SPF configuration. "v=spf1 ip4:67.212.170.242 -all" But verification connections come from a different address.

I'm surprised to see the opposition to self-signed certificates from the EFF. Pushing people towards centralized certificate authorities seems to be anti-freedom. Maybe there is a decentralized approach instead.