I use Proton Mail, which is a secure mail service. For paid contributors, they offer the ability to link the DNS record of a domain that I own to their system, so that I can use the proton mail system as "the official" mail for that domain.
This means that sending email to
my_address@my_personal_domain.tld results in the mail appearing in my
protonmail.com inbox. And I can send in the other direction as well.
The setup for this is somewhat involved, and takes an hour or so because you have to edit the DNS records for your domain, and those records have to propagate around the world. In theory, it could take a few days during a time of internet stress. However, there are nice hand-holding illustrated step-by-step instructions, so I was able to do it with no problems.
I recommend Proton Mail for a bunch of reasons unrelated to this. So I certainly don't have a problem recommending them for this, too! :-)