Performant & clean
Built in Rust with GTK4 & libadwaita. Instant startup, buttery scrolling, and an interface that stays out of your way.
Vireo is now Hylki — new name, new icon, same app. What's a hylki and why the change →
A modern email client for the Linux desktop
Hylki is a fast, GNOME-native email client with a three-pane layout, unified inbox, and support for OAuth accounts. Fast to open, effortless to read, and private by default.
- Open source · AGPLv3
- Zero telemetry
- GNOME-native Flatpak
GNOME Online Accounts & OAuth
Hooks into the accounts you already set up in GNOME Settings — sign in once, and Hylki is ready to go. Gmail and Outlook / Microsoft 365 use modern, token-based sign-in: no app passwords, no fuss.
IMAP push
Real-time delivery over IMAP IDLE. New mail lands the moment it arrives — no polling, no waiting.
Unified inbox
Inboxes, Starred, Sent, Drafts, Archive, filtered folders and tags each combine every account into a single list, or open to any one account when you need to. The sidebar remembers how you left it.
Message threading
Conversations are grouped into tidy threads, so long back-and-forths read top to bottom without the clutter.
GNOME Contacts & smart compose
Integrates with GNOME Contacts and autocompletes recipients as you type — fully keyboard-navigable, so you can pick an address without ever leaving the keyboard.
Gravatar avatars
Optionally show sender avatars via Gravatar for a friendlier, more scannable list — and flip it off with a single toggle when you’d rather make no avatar lookups at all.
Attachments gallery
Browse every attachment across all your inboxes and folders in one visual grid — image thumbnails and colour-coded file icons — with a full-size preview and a jump straight to the source message.
Mail filters
Rules that sort incoming mail by sender, subject or recipient into folders of their own, with live unread counts. Edit them any time, and surface a rule’s folder under All Inboxes.
OpenPGP, end to end
Read encrypted and signed mail, sign and encrypt what you send, and manage keys from Settings — through the GnuPG already on your computer, with nothing decrypted ever written to disk.
Tags
Label messages with coloured tags, alongside their folder. Stored on the server as IMAP keywords, so Thunderbird and your phone see the same tags — and rules can tag mail as it arrives.
Customize fonts and colours
Show every message in the font, size and colours you choose, with pictures kept and a per-message switch back to the sender's look.
Cloud attachments
Send big files as links. Connect Nextcloud, ownCloud, OpenCloud, OneDrive, Dropbox or Seafile in Settings and the composer uploads to your storage, shares a public link with an expiry and optional password chosen per email, and drops it into the message.
Send later
Pick tomorrow morning, Monday, or any date and time from the Send button's dropdown. The message waits in the Outbox, where you can still edit it, send it now, or delete it, until its time comes.
GNOME Files integration
Select files in GNOME Files, right-click, and pick Send with Hylki: a new message opens with them attached. Settings installs the Files extension for you, and the file manager's own “Send by email” opens the same composer.
In your language
Hylki speaks English, French, German, Greek, Hungarian, Portuguese (Portugal and Brazil), Russian and Spanish, and follows your desktop's language or the one you pick in Settings. The translations come from the community; to add yours, see issue #155.
Privacy-first
Email privacy baked in.
Hylki is built to respect you. No accounts to create with us, no data harvested, nothing phoning home. What happens in your inbox stays on your machine.
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Zero telemetry
No analytics, no tracking, no “anonymous usage data.” None.
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Remote content blocking
Tracking pixels and remote images are blocked by default, with a per-message “load” banner and a per-sender allowlist.
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Credentials in the system keyring
Passwords and tokens live in the OS secret service — never in plaintext on disk.
0trackers, pixels & telemetry pings
Vireo is now Hylki
Same app, same code, new name and icon. Here is what a hylki is, why the name changed, and what it means for you.
What's a hylki?
Hylki (pronounced HIL-kee) is Icelandic for a case or capsule: the shell that holds and protects what is inside. For an email client with an envelope icon, that metaphor feels just right.
Why the change?
Another project, an email app for macOS, chose the name Vireo about a month before this one did. Its maintainer got in touch, and while the clash was a complete coincidence, the fair thing to do was to pick a new name. The candidates were discussed in the open with the project's contributors, and Hylki won out: unique, not used by any other software, and true to the icon. Read the discussion on GitHub.
What it means for you
- Vireo 1.34.0 is the last release under the old name. Updates continue as Hylki, from version 1.35.0 on.
- Install Hylki once; nothing to set up again. Hylki is a separate install that sits alongside Vireo. Its first start carries your accounts, settings and cached mail across, and leaves Vireo untouched until you remove it.
- Then remove Vireo. Once Hylki is running with your accounts,
flatpak uninstall co.hyprlab.Vireotakes the old app away. If Vireo was your default email app, choose Hylki under Default Apps in Settings. - Same project, same people, same licence. The code, the AGPLv3, the GitHub repository (now hyprlab/hylki, old links redirect) and the Flatpak repository are all the same; only the name on the door has changed.
Free & open source, forever
Hylki is released under the GNU AGPLv3.
The Hylki Manifesto
Hylki exists to fill a need in the Linux desktop community for a modern, GNOME-native email client that doesn't sacrifice aesthetics for features.
The project has the following foundational values that guide its development:
- Hylki is committed to free and open source software. Hylki will never be for sale and is committed to remaining that way through our AGPLv3 license adherence.
- This project is community-driven and committed to putting humans at the center of everything we do. Our aim is to improve the lives of our users and the Linux desktop as a whole.
- We are committed to GNOME-first development ensuring 100% compatibility with the latest GNOME release. This app was conceived for GNOME and it will remain the desktop environment we target primarily.
- Aesthetics matter as much as features. Hylki should make using email on the Linux desktop both visually pleasing and enjoyable through consistent and familiar UI/UX paradigms. New users to GNOME should be able to intuit how to use the app without needing to refer to documentation.
- Feature-rich and choice-forward philosophy. Providing means for the user to maximally customize the app's feature set is a high priority. We maintain that Hylki is both beautiful and highly functional to tackle every email edge case.
Built with AI, shipped by a human
Most of Hylki's code is written with Anthropic's Claude — directed, reviewed and tested by a human maintainer who signs off on every release. The artwork is human-made: the app icon and the wordmark are drawn by Yiannis Ioannides. And the app itself contains no AI: no AI features, no requests to AI services, and your mail never leaves your machine. Read the full AI notice →
With thanks to Hylki's contributors
Open source means the app is shaped by the people who use it. These folks sent patches that ship in Hylki today — credited on every release and in the app's About window:
- Anton Palgunov — sender avatars from your GNOME Contacts, and GNOME Online Accounts refinements
- Isaac — PDF thumbnails, the attachment-opening fix, the reader's To line, and the remote-content preference
- Alfonso Lizárraga — sending to punctuated recipient names, the startup message list, and the unread dot
- Chris Pouliot — Proton Bridge connections
- Alexander Lubovenko — Gmail conversations, and a thorough security review
- frenchy82 — the French translation, Hylki's first
- Laszlo Lang — the Hungarian translation
- Ilya Semenkovich — the Russian translation
- Daniel Miguel — the Spanish translation
- Christian Lauinger — the German translation, and New Message in the launcher's menu
- Paulo Fino — the Portuguese (Portugal) and Brazilian Portuguese translations, and the language chooser request
- Yiannis Ioannides — the app icon, its symbolic twin and the wordmark; the Flatpak install fix; and the requests and design feedback behind tags, split replies and the reader's own font and colours
And not every contribution is code — thanks to p-mitana for a thorough round of design feedback and bug reports that shaped Hylki's reader and composer, and to everyone who files issues and ideas.
Pull requests are welcome — see how contributions are credited →
Install Hylki
Choose between Flatpak or RPM. Both keep updating through GNOME Software, from this site's own repositories.
What you’ll need
- 64-bit Linux, Intel/AMD or ARM. Both
x86_64andaarch64(ARM64) are published — Raspberry Pi 4/5, Snapdragon X Elite laptops and ARM virtual machines included. The install file below picks the right build for your machine automatically; there is nothing to choose. - Flatpak, with Flathub enabled. Hylki installs from hylki.hyprlab.co, but it runs on the shared GNOME 50 runtime hosted on Flathub — so installing pulls that runtime the first time. Your distro version barely matters as a result; even older LTS releases work.
- A Wayland or X11 session. Wayland-native, with an X11 fallback.
- A Secret Service keyring (GNOME Keyring or KWallet). Passwords and tokens live here, never on disk — sign-in won’t persist without one.
Recommended: working GPU drivers (OpenGL / Mesa), ~4 GB RAM, and a GNOME-style desktop — though it runs fine on KDE and others. Uses ~1.1 GB for the shared GNOME runtime (reused across your Flatpak apps) plus ~13 MB for Hylki. OAuth account sign-in support and contact autocomplete use GNOME Online Accounts and GNOME Contacts integration.
Will it run on my distro?
100% compatible — works out of the box
Fedora, RHEL, and their relatives (Rocky, Alma, CentOS Stream, Nobara, Silverblue…) ship GNOME, the GNOME Keyring, and Flatpak with Flathub already enabled. There’s nothing to set up — passwords are remembered. Just install Hylki:
flatpak install --from https://hylki.hyprlab.co/flatpak/co.hyprlab.Hylki.flatpakref
100% compatible — works out of the box
The Fedora KDE (Plasma) spin ships Flatpak with Flathub enabled and uses KWallet as its Secret Service keyring, so your account password is remembered with no extra setup. Just install Hylki:
flatpak install --from https://hylki.hyprlab.co/flatpak/co.hyprlab.Hylki.flatpakref
One-time setup, then fully compatible
Ubuntu doesn’t enable Flatpak or Flathub by default (its App Center is Snap-based), so add Flatpak support and GNOME Software’s Flatpak backend first. You only do this once.
- Install Flatpak and the GNOME Software Flatpak plugin (this also pulls in GNOME Software itself):
sudo apt install flatpak gnome-software-plugin-flatpak - Add the Flathub remote — Hylki pulls the shared GNOME runtime from it:
flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo - Reboot (or log out and back in) so Flatpak support is fully active.
- Install Hylki:
flatpak install --from https://hylki.hyprlab.co/flatpak/co.hyprlab.Hylki.flatpakref
Ubuntu already includes the GNOME Keyring, so your account password is remembered automatically after that.
One quick keyring step, then fully compatible
Linux Mint already includes Flatpak and Flathub, so Hylki installs out of the box — click Install Hylki above, or run:
flatpak install --from https://hylki.hyprlab.co/flatpak/co.hyprlab.Hylki.flatpakref
Make passwords stick — and stop the login prompt
On Mint’s Cinnamon desktop the system keyring often needs a one-time setup, or Hylki can’t remember your password between launches. Hylki 1.3.7 and newer detect Mint and show this tip in-app the first time you add an account.
- Install the keyring tools if they aren’t already present:
sudo apt install gnome-keyring seahorse - Open Passwords and Keys (Seahorse) and make sure a keyring named “Login” exists and is set as Default (right-click → Set as Default).
Stop it asking for a password at every login — pick one:
- Recommended: set the Login keyring’s password to match your user login password (right-click → Change Password), and sign in with your password rather than using automatic login. The keyring then unlocks itself when you log in.
- Or: set the Login keyring’s password to blank to remove the prompt entirely — convenient, but your saved passwords are then stored unencrypted at rest, so only do this on a machine you trust.
100% compatible — works out of the box
Zorin OS is GNOME-based and ships Flatpak with Flathub and the GNOME Keyring already configured. Hylki installs and runs with no extra setup — passwords are remembered. Just install it:
flatpak install --from https://hylki.hyprlab.co/flatpak/co.hyprlab.Hylki.flatpakref
Found a bug or have a feature idea? The best way to reach the project is to open an issue on GitHub. Please search existing issues first, then include your Hylki version, your GNOME version and distro, and the steps to reproduce.
Hylki is free and open source. If it makes your inbox a little better, consider supporting its development at the link below. Thank you!
Install Hylki beta
The beta channel ships upcoming features before they reach the stable release.