Ltt.rs (pronounced Letters) is a proof of concept email (JMAP) client currently in development. It makes heavy use of Android Jetpack for a more maintainable code base than some of the preexisting Android email clients. To use Lttrs you need a JMAP (JSON Meta Application Protocol) capable mail server! Features & Design considerations: · Heavily cached but not fully offline capable. Ltt.rs makes use of JMAP’s great caching capabilities. However actions, such as marking a thread as read, need a round-trip to the server until their consequences like unread count are updated. Ltt.rs will ensure that the action itself won’t get lost even if performed while momentarily offline. · No settings aside from account setup. Settings invite feature creep and make the app hard to maintain. Ltt.rs aims to support one specific work flow. Users who desire a different work flow may find K-9 Mail or FairEmail more suitable. · Minimal external dependencies. Third party libraries are often of poor quality and end up being unmaintained. Therfore we will only rely on well known, well tested libraries from reputable vendors. · Autocrypt as a first class feature¹. With its strict UX guidelines autocrypt fits right into Ltt.rs. · Ltt.rs is based on jmap-mua, a headless email client, or a library that handles everything an email client would aside from data storage and UI. There is also lttrs-cli which uses the same library. · When in doubt: Look at Gmail for inspiration. ¹: Planned feature Ltt.rs is licensed under the Apache License 2.0. The source code is available on Github: https://github.com/inputmice/lttrs-android