> HTTPS is end to end encryption. In the instances that SMTP traffic is encrypted, it's only node to node. So in this instance SMTPS is less secure than HTTPS.
Sorry, not following you. HTTPS and SMTPS are both end to end encryption schemes. In fact they both use SSL in a similar way to secure traffic.
> It's still not /the/ standard though, just /a/ standard; and one that's not particularly well supported in my experience.
Really? Strange. I transmit binary data every day over email and I've never had an issue with a recipient not receiving it.
Which mail server and version in particular are you having issues with?
In general almost all of the "big names" in mail servers support more than just base64 as standard.
> yes, but those response codes are rarely transmitted back up the stack
I'm looking in my mail server logs right now, and am seeing a response code from a third party server for every email we forward. Our mail server then determines what to do with each code, and I can manually add additional handlers (e.g. code XXX do THIS, code YYY do THAT).
> I know SMTP isn't designed to be real time. But there's absolutely no reason why e-mails shouldn't be real time in the modern world.
Cost is a reason. Delivery assurance is another (e.g. if it fails to deliver the first time, do you retry for hours or just give up?). The fact that some clients are still on slow/off-line connections is a very good reason (e.g. phones that come in and out of cellular range, people on dial-up, people out in the middle of nowhere who get internet for an hour once a week, etc).