Mailchimp recently announced that it is changing its free plan, reducing the number of contacts and sends that can be managed for free. Because of this, wmtc will no longer qualify for the free level.
As I said when I switched to Mailchimp two years ago:
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 so that people can read a free blog!
I did some research in my usual scattershot manner, and found Zoho. Zoho's free level can accommodate wmtc's subscriber list and has a good reputation for reliability.
It's possible that there may be some duplicate emails, as I end the Mailchimp sends and set up Zoho. Apologies in advance.
Pro tip: Forbes' listicles are proving to be very useful. I've used them for several things lately and they've been very good.