Most people are not capable of running their own mail server. The convenience of services like Google, plus the risk of turning your mail box into a spam machine, vastly outweighs the downsides for most people.
> Most people are not capable of running their own mail server.
I think that is a big part of the problem. It should be relatively straightforward for someone who isn't a full-time email server administrator to setup a mail server correctly, but it's not. At least, it wasn't easy last time I tried it with Postfix and (iirc) Courier on Ubuntu. All the cryptography options are disabled by default and you have to spend a lot of time figuring out which ones should be turned on, where to stick the certificate files and how they should be formatted, how to get Courier and Postfix to talk to each other, etc...
Maybe there's an easy solution (besides "pay someone a monthly fee to manage this all for me") that I'm oblivious to, but it seemed like I was on a well-travelled path and it was a lot harder than it should have been.
http://arstechnica.com/information-technology/2014/02/how-to...
It shows how to set up SPF, DKIM, TLS, anti-spam filtering, Sieve, certificate-based authentication (I still haven't figured out how to do this with an iPhone), and so on. The only bolt-on it references but doesn't explore and I actually used is the Z-Push package to implement ActiveSync.
Do you encrypt the email on disk, or are they stored in plain text?
That, I think, is why the distribution managers don't make the default configurations a little more friendly/sane; most users aren't interested in installing a MTA to do anything but local delivery or smarthosting, and the people who are, are probably going to tweak the configs to death anyway, so it's not worth spending the time making it run well and securely straight out of the box.
It wouldn't be too hard to build a "mailserver in a box" with (say) Debian + Postfix + LetsEncrypt + BIND that you could stand up in an hour and be reasonably secure (and I'd be kinda surprised if that doesn't exist in some form already), but I don't know how many people would want it who aren't running mailservers already, and have the capability of doing so.
As with so many things in AWS, it's left up to the customer to inform AWS that a) you're running a mail server, b) what the purpose/use case is and c) request they configure the reverse lookup associated with the elastic IP you've allocated.
Source: I've been running public facing SMTP servers in EC2 for years with no issues.
https://aws.amazon.com/ses/faqs/
Still, unless you're running a server for a lot of people and you have tons of free time, you'll discover that it's more expensive than paying any of a bunch of people to take care of email for you.
Source: I work at FastMail
I'm having high hopes for Ubuntu 16.04 having a more recent version on board. Then I will try to switch from postfix again. Because as you've said, it's really straightforward to set up :)
Certs weren't free for business use until let's encrypt.
The pervasiveness of self-signed certificates for SMTP servers means that rejecting them would drop large amounts of email. STARTTLS is basically useful for thwarting passive collection of network traffic.
And if I can point your MX records there, via hijack or any other means, then I have a valid SSL certificate for receiving your email.
DKIM (which does not use a CA-issued certificate, it uses a public key published in DNS) is the technology that's intended to authenticate the email sender. It still wouldn't stop phishing attacks where the purported email sender is something like "admin@facebook-account-verification-2016.net" though, and I don't know that there really is a good technical solution to that sort of thing.
Except everything you send and receive with your Gmail account is read by them and whatever government agencies anyway... So what's the point?