Requiring DMARC may be good, but Outlook's approach is awful.

I was working for Microsoft when outlook.com launched and got a good email address that was my primary for more than a decade.

I had so many issues with things getting silently dropped with no recourse (2FA codes, account recovery mails, etc.) on so many sites that I finally gave up, reversed the stream, and had Outlook forward to GMail instead of vice versa. A few months after that, I realized that all my Outlook got was an enormous volume (hundreds of day) a spam and that all legitimate mail was going to my other accounts, so I turned it off entirely and haven't read that mailbox in over a year.

no matter how much you pay for VPS or which cloud you use you'd get same treatment

Stop being so ignorant

Some hosting providers are known for not caring about the activities of their customers, but in general, how would I know that the other tenants are scum?

I have access to a fairly large dataset of known bad hosting providers, but most people don't. So how do you tell the difference between getting a good deal and "this is cheap because it's sketchy as all hell".

We also don't block all of Vietnam, or all Jio customers in India, even if we know that 20% of bot traffic is from those two alone.

> This is not Microsoft's fault.

Wait until this guy realizes that all spam these days comes from Azure ASNs, and abuses cross-tenant issues as well as a simple "Fwd: ..." and "Re: ..." tricks to bypass Microsoft Outlook spam filters.