You’ve heard of SMTP, I’m sure. It’s hard to use the internet without at least having heard the phrase once or twice, even if it’s when you’re jabbering away with tech support because you can’t send mail.
A recent Internet Draft, published about 2 weeks ago, proposes a new “AMTP” (“Authenticated Mail Transfer Protocol”). I read through the draft, it’s pretty neat stuff. I can only see a couple of (small) problems with it.
First and foremost, the implementation described forces mail server administrators to work with a CA (certificate authority). This means giving money to someone for a signed X.509 certificate, so that you can establish a TLS connection with other AMTP servers. If the CAs decide to price these X.509 certificates high enough, it’ll basically kill the protocol.
Secondly, it pretty much kills the home user who doesn’t wish to use his ISP’s mail server (like me) for whatever reason (i.e., they force you to use an Envelope-To encapsulation). Based on the specification in the Draft, all mail servers must have synchronized DNS and rDNS records: if mail.example.com’s A record is 10.10.10.14, then 10.10.10.14 must be a PTR for mail.example.com. This can cause problems with ISPs who won’t (or can’t) provide proper reverse DNS for their customers. It also has the (theoretical) possibility of causing problems with a sysadmin who didn’t have enough coffee; make a typo in a zone file, and your mail server suddenly won’t work.
On the whole, though, I like it. Especially if it cuts down on the amount of spam that I get on a daily basis.
