> But there's also a problem: I now have Thunderbird exactly how I wanted it, but it took a few hours to set it up and it required some technical knowledge: calendar, tasks, Gmail like smart search, multi language corrections. For a normal user, that might be off-putting. However, I think Thunderbird is gaining momentum again
Thunderbird's problem is and always has been a lack of resources. Mozilla infamously bungled, underfunded, and then abandoned it (as a result of narrowing their focus from "the Internet" from their original charter and trying to redefine "Internet" to mean "the Web"). But even after the spin-off and independence, Thunderbird's lack of resources isn't helped by Thunderbird development being more difficult than it needs to be (read: seemingly unapproachable for many potential contributors).
"How to keep contributors when they are not even contributors yet" by Soledad Penades is incredibly relevant (moreso for its title than the actual specifics of the post content, but there are good lessons there, too):
https://soledadpenades.com/posts/2015/how-to-keep-contributo...
Ten years ago, you could get folks who were willing to get dirty with XPCOM/XBL/XUL because they already existed in the wider Mozilla community, and the biggest problem was Thunderbird's build process and compile times. Nowadays, you have the same barrier wrt annoying build processes, but the pool of knowledgeable people is smaller since the XUL add-ons ecosystem has been decimated. Ultimately, Thunderbird will need to address its legacy use of XUL, but they already know that and seem to be working on it.
More importantly, though, the problem Thunderbird needs work on is the same old problem from before: the headache of setting up a development environment that can actually perform a successful build, and how long it takes for that build to complete. The way that Zotero is built is currently pretty hacky, but nonetheless an example of how easy it should be to get a development environment set up. (In fact, it can and should be made easier than that, but just getting Thunderbird's build process to where Zotero is right now would be a huge boon to making Thunderbird something that potential contributors actually start considering as "approachable".)
https://github.com/zotero/zotero-standalone-build/blob/maste...