I posted about this, looking for input from other bloggers about how they are handling this. I must have been unclear, because I heard mostly from readers, telling me they don't subscribe by email, and so will not have a problem. That's very good! But didn't help my dilemma.
The only email service I was familiar with was Mailchimp, which is used by many grassroots and nonprofit groups to manage mailing lists and communicate with their subscribers. I've used Mailchimp with a few different groups. It's very easy to use, and has a lot of great functions even on the free level. But I thought Mailchimp would be overkill for my needs.
I also don't want to pay for a service. I have many paid subscriptions; I don't expect to get everything for free. But since I do not (and never will) have ads on this blog, it doesn't generate income. I write for free and you read for free. All good. But I'm not going to pay for people to read a free blog!
I researched all different subscription services, and when all was said and done, I chose Mailchimp. I found nothing better -- not even close.
Bringing the list of wmtc subscribers to Mailchimp also has the hidden advantage of giving subscribers an opportunity to unsubscribe, and cleaning the mailing list of defunct email addresses. I expect my mailing list to shrink a lot, but at least I'll know that everyone who subscribes actually wants to -- as opposed to people who stopped reading 10 or 15 years ago.
I plan to keep this very simple. Current subscribers will get the option to sign up for the new list or to unsubscribe. Subscribers will receive an email whenever a new post is up. The end. I hope!