Then EVERYONE stopped because it's awful. Modern ISPs don't like SMTP floating around, (DKIM, DMARC, SPF) are a pain to maintain over time, exploits will happen, and your free off-the-shelf virus and spam filters suck compared to the big companies seeing billions of messages per day.
FWIW, i used mail cow [0], which was a delight to setup and use. And it comes bundled with a decent-ish material design webclient.
I would love to go back to hosting my own mail server though. As of now, i shut it down, and use gsuite.
This is the type of nonsense I expect from HN. Well done.
It is entirely reasonable to show how you've handed your mail to gmail and they refused it without actionable explanation, so it is a problem between the recipient and gmail.
Assigning blame is done after the fact to make up for a mistake.
Just avoid the mistake.
If I get an explanation from the server I will fix it. I get dmarc reports and I make sure all pass. That's all I can do.
gmail spam filtering is quite bad, in both directions. Legit email goes to spam (even when sent from gmail itself) and spam does get through.
The basic open source tools are actually very, very good at it. I get about 0-2 spams a month, everything else is caught by either my postfix configuration or by spamprobe. And I never get legit email in my spam spool.
This is a much better success rate than what I observe at my gmail account.
The latter will catch new spam tricks easier. But the former will be trained by you. For you. For your niche, using your lingo and so on.
To take an extreme example: let's imagine you are the ITperson for a doctors' practice aimed at people with sexual disfunctionality. One thing is for certain: using Google or Outlook for your mail is a disaster waiting to happen.
Those "specialized tools" make email viable. Without it, everyone would be spoofing everything and you wouldn't use email anymore.
from what i understand, the gmails, yahoos, outlooks, whatevers of the world basically make it hard on purpose to make their own jobs easier.