Er, no, it seems anti-spam. The fact of the matter is, plenty of people use dime-a-dozen hosting to make spam bots. These days, you're better off using a reputable mail service as opposed to rolling your own, unless you have a fairly large company.

It is anti-spam, but it is also anticompetitive to block anyone that isn't gmail or an already known big player in that space. Apparently lots of people are having trouble setting up a mail server on their own without getting blocked by Google. Can you see that as a problem for the intent at large? I wonder what kinda marketshare gmail has.

It's probably a problem they aren't in a hurry to solve either.

I mean it's not that you're automatically blocked it's just that your server's score for sending email is nonexistent which means a high likelihood of being a spam server.

You have to spend a long time to build up a reputation to get places to mark your email as not spam. This is why many providers that allow you to do bulk email through them have multiple IPs and they only let the most behaved on their better reputation IPs.

It's probably a problem they aren't in a hurry to solve because there's no reason to solve it. Any decently-funded small business can afford to use proper web hosting (Er, I love Digital Ocean. But they aren't really "web hosting").

Google (and basically every other reputable email host _and_ every "independent" email host) are blocking mail from services that host cheap compute power. A lot of Azure and GCP email traffic would likely be blocked, not just Digital Ocean.

If you want to start an email service, use something that isn't a known platform for spammers.