I looked at e-mail distribution options, and frankly, none were appealing. The most radical solution was to set up a free Substack to use their mailing list service. I still have a few weeks to set it up, and will have to make a decision soon.
Unfortunately, I just checked my existing email subscription list, and it is heavily infested with bogus accounts. (These are mainly from "outlook.com.") Given my concerns with that list, I doubt that I will import it into whatever replacement I go with, and so people will likely need to opt in to the new one.