[bad_user]

Thunderbird is still under active development, I'm one of their users, being the best email client for the desktop. Unfortunately Thunderbird is also a dead end, being incompatible with Firefox's direction.

Yes, XUL is dead and Firefox is evolving into a Chrome substitute and while people have serious concerns about it, fact of the matter is that Chrome was designed for web apps and almost 9 years after its release Chrome is still the best browser available for web apps. Not sure how many people here remember Chrome's original goals, beautifully illustrated by their comic book announcement, but here's a refresher and try to count the problems that Firefox still has in 2017: https://www.google.com/googlebooks/chrome/index.html

In other words, Firefox is dying because users have been trained to expect security, stability, an interface free of crappy toolbars and extensions you can't uninstall, not to mention running long lived web apps. And while people on this forum will cry out for Vimperator or other poweruser extensions that 99.9% of the world have never heard about, it's undeniable that without evasive action Firefox will become a footnote in only a couple of years.

I'm also a Firefox user and I understand their move away from Thunderbird. For work I use Gmail, personal email is Fastmail, both have really good web interfaces. And while I try using email clients like Thunderbird, the web interfaces are simply good enough and always there. These are web apps btw and guess which browser is best for web apps? It's not Firefox ;-)

And for all I care Mozilla can kill every project they have, if that means Firefox continues to improve. Because it's still the only browser that cares about my freedoms.

[jwr]

As a data point, my webapp (PartsBox.io) works best/fastest in Safari, Chrome is second, Firefox a distant and slow third. So, I'd take issue with the statement that "Chrome is the best browser available for web apps", at least on MacOS, and at least for some web apps (I know WebGL apps work better in Chrome).

[jeena]

But gmail and fastmail don't work offline.

[Brakenshire]

That is only because they haven't yet caught up with the technologies available to them. Are there are email web apps that have adopted Service Workers? Although to be fair that's not going to work well for keeping a large offline archive.

[rodorgas]

You can have GMail offline by installing the Chrome App.

[bad_user]

The only time I find myself offline is when I'm flying. Not that big of a deal.

[Accacin]

So you don't need or require backups of your emails offline?

[bad_user]

For personal email I don't care that much for backups, I trust Fastmail to do it better than me.

I do use Thunderbird for offline backups, more because of the thought of losing important work email. But without combining it with an actual backup system, that's not actual backup, because IMAP does synchronization and messages deleted on the server translate to messages deleted on the client side as well. So I combine it with Arq Backup, which does daily uploads of everything on my laptop.

I do wonder whether using Thunderbird for backups is wise. I never recovered from a Thunderbird archive. Sometimes I'm thinking that a solution like OfflineIMAP or mbsync/isync might be better.