Unsurprisingly, Amazon is now running a mail spamming service
I recently got email from an
amazonses.com machine, cheerfully
sending me a mailing list message from some random place that
desperately wanted me to know about their thing. It was, of course,
spam, which means that Amazon is now in the business of running a
mail spamming service. Oh, Amazon doesn't call what they're running
a mail spamming service, but in practice that's what it is.
For those that have not run into it, amazonses.com is 'Amazon Simple Email Service', where Amazon carefully sends out email for you in a way that is designed to get as much of it delivered as possible and to let you wash annoying people who complain out of your lists as effectively as possible (which probably includes forwarding complaints from those people to you, which is something that has historically caused serious problems for people who file complaints due to spammer retaliation). I translate from the marketing language on their website, of course.
In the process of doing this amazonses.com sends from their own
IP address space, using their own
HELO names, their own domain
name, and completely opaque sender envelope address information.
Want to get some email sent through amazonses.com but not the email
from spammers you've identified? You're plain out of luck at the
basic SMTP level; your only option is to parse the actual message
DATA phase and look for markers. Of course this helps
spammers, since they get a free ride on the fact that you may not
be able to block amazonses.com email in general.
I'm fairly sure that Amazon does not deliberately want to run a mail spamming service. It's just that, as usual, not running a mail spamming service would cost them too much money and too much effort and they are in a position to not actually care. So everyone else gets to lose. Welcome to the modern Internet email environment, where receiving email from random strangers to anything except disposable email addresses gets to be more and more of a problem every year.
(As far as I can tell, Amazon does not even require you to use their own mailing list software, managed by Amazon so that Amazon can confirm subscriptions and monitor things like that. You're free to roll your own mail blast software and as far as I can tell my specific spammer did.)