Some services have a yearly plan where you end up paying the equivalent to about 4€ a month - protonmail is an example that comes to mind.

As a Thunderbird and K-9 user this is 51% good news and 49% possibly bad new.

Good news because it should increase the chances that the two products will live a longer life.

Possibly bad news because I'm one of the crowd that went back to K-9 5.600 because the new version destroyed the UI that was the primary reason why we picked K-9 over other apps. 100% self selection bias here. There was maybe an ongoing effort to offer the old interface as an option. I'm not sure Mozilla's going to invest into that. On the other side, the way I'm using Thunderbird is very close to the old K-9.

A wish: an IMAP server backed by Thundebird's local storage and K-9 as client.