
Thunderbird and K-9 Mail users will be allowed to sync email data from their existing accounts through Firefox Sync from summer 2023. Furthermore, both cketti and Sipes have decided to keep the project open-source therefore, due to shared funding, any donations sent to K-9 Mail will also be used by Thunderbird. While only for Android users right now, Mozilla has stated that support for iOS is being considered too. Now, K-9 Mail's maintainer Christian Ketterer, known as "cketti", has also announced that K-9 Mail will soon become Thunderbird. The project manager for Thunderbird, Ryan Lee Sipes, had recently publicized that this project was on its way.

Mozilla Thunderbird has announced that it is collaborating with K-9 Mail to bring its email client to Android.
