FYI this is from 2022 but is relevant because Thunderbird (and K9 v8) just landed in F-Droid (and other android package managers I guess but I haven't checked).
The process of importing from K9 Mail worked without issue for me. There is also the option to import from desktop using a QR scanner (or some kind of scanner, again I didn't go down that rabbit hole).
How did the K9 project never talked about this? Its public since 2 years or so that Thunderbird announced they are working on rebranding K9 as Thunderbird.
Just FYI I installed the apk from the github repo (not the google play version) via Obtainium a few days ago and it tried to make a connection to 2 cloudflare IPs during setup of my account. Without prior consent or any mention. So just be aware that there is still some form of telemetry or unwanted connections happening, even though they removed the telemetry flowing to Mozilla's own telemetry endpoint.
K-9 had zero of this, it just spoke with your mail servers and that was it.
So be careful and block outgoing app connections by default. I did not analyze the data being sent, just that there were those 2 unwanted connectiins happening.
Isn't this part of the auto configuration stuff? Basically there's a standard where you can add some DNS records to your domain and/or a standard file on your website so e-mail clients can automatically prepopulate all the email settings so you only need to worry about entering your email and password.
I think it's weird that they insisted all along that K-9 would remain its own branded version of the joint app. Yet according to f-droid, my newly updated K-9 (same app I've used for a decade and a half) is now one of two "Thunderbird for beta testers" listed...
It's still K-9 in my local app menu, the icon is the same, but I guess the Thunderbird project are sort of working out how to manage two differently branded versions of the same app?
Thunderbird is finally out of beta so you can get it through the play store or F-Droid. K-9 itself was also updated so it's now basically a K-9 branded version of Thunderbird.
Idk about other sources, but I get my apk directly from GitHub via Obtainium, and my app recently changed from K-9 Mail to Thunderbird. Icon, app name, and app theming changed. This has been in the works for a while but seems like they're officially switched the apk.
Will I be able to sync my Thunderbird accounts with K-9 Mail?
Yes. We plan to offer Firefox Sync as one option to allow you to securely sync accounts between Thunderbird and K-9 Mail. We expect this feature to be implemented in the summer of 2023.
So is this sync functionality already available? (Edit: Citation corrected)
Its been in testing for a bit. It got bumped from the last major desktop Thunderbird release and since Thunderbird releases used to be synced to firefox ESR releases its been a slow turnaround to get their schedule moving faster.
Mozilla is non-profit. I wish they could sell it as a one-time or something as I dont mind supporting them if they're doing useful capitalistic things like that. Very few actually private mail client apps for iOS. I only know of two and Canary is not one of them