[wakawaka28]

Technically having your own domains is superior, but it can be difficult to get past spam filters if you have your own domain. Not least because Google and Microsoft often automatically trash anything from custom domains. If you're ok with the delivery issues that can come with this setup, it's better. But personally I get really pissed off when my mail does not get delivered for any recipient.

[mr_windfrog]

You're absolutely right, ending up in spam is a real pain. I've run into the same issue myself with custom domains; even when everything is set up correctly, delivery can still be unreliable.

[tatersolid]

This is more about reputation than “custom domains”. I’ve had <realname>.com registered since 1996. Hosted at free Google Workspace account for 15+ years. They added SPF and then DKIM/DMARC as those thigs evolved. Never had spam reports in all that time; delivery is better than $dayjob’s 30-year-old domain.

Reputation is everything in email delivery.

[wakawaka28]

I set all that stuff up for mine, and used a reputable mail server (FastMail), and even went through steps particular to Microsoft and Google. Google started accepting my emails, but my employer's Microsoft Exchange system kept sending my stuff to spam. How many other people would just not receive my stuff? It's impossible for me to know. If you want to reach out to strangers, any false positives will hurt you.

[tatersolid]

That might be from a Microsoft feature to prevent phishing that blocks display name spoofing. I get hit with that when I email from my personal to work email… the display name portion of the FROM address matches my work so it trips this filter.

Obviously they can only do this for unique-enough names and so this filtering could never work for “Joe Miller” but it does stop the dozens of phishes we see per day that are FROM our CEO’s first and last name but with a Gmail email address.

[wakawaka28]

I don't think it's anti-phishing. If it is, then it's a broken rule. I have registered FastMail as my mail server properly with my DNS (MX record, I think) and also done the other authentication stuff. This is not a case of merely setting the FROM field, as many people do. You can set the FROM field of a message to anything if your mail server allows this. The receiver might reject this, but it is/was a common way to configure your mail client in the past because of stuff like email forwarding. Lots of people use 3rd party mail providers whose servers are not under the same domain as the mail being served. I think most people with custom domains do not run their own mail servers, and thus point their MX entries at a 3rd party mail provider just like I do.

I don't know why this stuff would be rejected. I went through several debugging steps online and didn't get anywhere with it. Every tool said I had set it up correctly.