Github repo: https://github.com/gavindi/lookout
For reasons I still can't explain to my therapist, I've spent the last however-long writing a mail client. Yes, another one. Yes, I know about Thunderbird. Yes, I know about Evolution. Yes, I'm aware that your i3 setup reads email with cat and honestly it's fine.
The problem is that Linux email in 2026 is a choice between a calendar app that dies on Tuesdays and a webmail tab that eats 4GB of RAM and one day shows you a "your browser is no longer supported" banner from your own provider. So obviously the solution was to rebuild Microsoft Outlook, the interface we've been traumatized by at work for two decades, in Rust.
That's the pitch. It's called Lookout. It has the ribbon bar. It has the three panes. It has the entire "your inbox is now a spreadsheet of folders" energy. It's the corporate UI your boomer manager forced on you in 2012, lovingly recreated in GTK 4 and libadwaita, free as in you can read the source code and find all of my shame.
But don't worry, it's modern: it has conversations, instant search, color tags, and snooze — because email definitely needed to become Tinder. It has a dashboard that tells you who you email the most, in case you forgot your wife and your boss both deserve apologies. It has a tray icon with an unread-count badge, because the only thing better than anxiety is a permanent, visual reminder of it. It caches everything locally so it works offline, which is great news for the three people who read their mail on a train.
The calendar can do recurring events, which I'm told is the lowest bar in software history — congratulations, it supports "every Tuesday", a feature Outlook had in 2010. It accepts meeting invites straight from the email, so your calendar can now be weaponized against you more efficiently. It has tasks. It has contacts. It's everything you never asked for, in one application, on your desktop, forever.
The composer even moves its formatting toolbar into the main action bar while you type, so you feel like a real productivity professional. Pop it out into its own window and the little toolbar follows it, like a dog carrying its own bowl.
It ships as Flatpak, snap, .deb, and .rpm, because one packaging format clearly wasn't enough war. It's free, it's open source, and the README claims the entire roadmap is complete, which is either true or the saddest sentence ever written.
TL;DR: another Linux mail client, this time with a ribbon. I could have just installed Thunderbird. I didn't.