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Thunderbird is coming to Android – in K-9 Mail form

Rumble heard as two faithful friends merge into lycanthropic chimæra

The cross platform email client Thunderbird is to launch an Android version, which will be based on the existing K-9 app.

A month after Thunderbird's product manager, Ryan Lee Sipes, tweeted that a mobile version of the email client was "coming soon", the project has announced how it will do it.

It has acquired the FOSS Android email client and one-time Register app of the week K-9 Mail, which will become Thunderbird for Android.

The Thunderbird Foundation has hired Christian Ketterer, known online as "cketti", developer of K-9.

Thunderbird users have been asking for an Android version for years. This is an unexpected route to get there, but it's a viable one: K-9 is a well-regarded app, and one of the very few Android apps to handle traditional bottom-posted email.

This is important to heavy internet email users, who are often the same sort of people who favour open-source and cross-platform tools – such as Thunderbird. Tellingly, K-9 mail is also the basis of the email client in the /e/ Foundation's de-Googled smartphone.

The Mozilla Foundation spun off Thunderbird in 2017, but continues to back it and the program is undergoing active development.

According to a recent blog post, the Thunderbird Project's finances are healthy.

Sipes confirmed that Apple iDevice owners will have to wait a little longer: for now, K-9 Mail is an Android-only app. However, this is arguably less urgent, as iOS and iPadOS come with a standard email client, which is fairly capable. It may also be more difficult, given Apple's prohibition of competing web-rendering engines on iOS – although that faces EU legal challenges.

The Thunderbird project has published an FAQ page about the deal, which contains one very promising detail:

"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."

Synching between Thunderbird installations is a long-felt want among Thunderbird users, first opened as bug 46444 a full 14 years ago – complete with a bounty on its head. After a decade and a half, it would be amusing if synchronization between desktop and mobile proved to be the spur for this to finally get implemented. ®

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