meli VS mail-builder

There's also https://github.com/meli/meli.

Try https://github.com/meli/meli/ it's mostly stable and doesn't have the problems described in the article. Development's on hold due to some personal factors but it's going to be picked up again.

I don't know if it counts as rich, but I rolled my own terminal UI in my email client meli [0]. There's a web demo here: https://meli.delivery/wasm2.html that is the client compiled to webassembly and the ANSI escape codes translated to equivalent SVG drawing so that you can try it on your browser. [0] https://github.com/meli/meli/

Meli. It's actively developed, looks good, has TUI, supports multiple accts, Maildir, mbox, notmuch, IMAP and JMAP. Need I say more?

My terminal mail client. Work has been slow but steady

https://meli.delivery

https://github.com/meli/meli

If you work with e-mail on your Rust projects, you may also want to check out mail-parser (E-mail parsing library), mail-builder (E-mail builder library), mail-send (E-mail submission library), jmap-client (JMAP client library) and sieve-rs (Sieve filter interpreter).

As a starting point you could take a look at the mail-parser and mail-builder Rust libraries.

I just released a new crate called mail-builder to easily generate MIME e-mail messages in Rust. This library combined with the mail-parser crate I had published some weeks ago provide full support for building and parsing RFC5322 e-mail messages of any complexity in Rust.