For years, Geary served as my default email client on Linux. While it offered a lightweight, simple interface with a modern GUI, it had notable limitations—particularly when used with tiling window managers. When the window wasn’t wide enough, clicking an email would consume the entire application instead of preserving the email list and sidebar. Additionally, on Pop!_OS, the application sometimes failed to appear until manually launching via command line.
These issues, though not deal-breaking, were consistently frustrating. That’s why I was eager to test Aerion, a newly released cross-platform email client available for Linux, macOS, and Windows.
Aerion is an open-source, Linux-first application that prioritizes privacy, efficiency, and simplicity. Sponsored by 3DF, a Hong Kong-based IT consultancy, the project maintains transparency through its publicly accessible GitHub repository. The interface is intuitive and well-organized, requiring no significant learning curve.
Aerion might not have a ton of features, but what it does have is useful.
Screenshot by Jack Wallen/ZDNET
What Aerion lacks in complexity, it makes up for in thoughtful design. The application supports numerous email services including Gmail, Outlook/Hotmail, Yahoo Mail, iCloud Mail, ProtonMail Bridge, Fastmail, Zoho Mail, AOL Mail, GMX Mail, Mail.com, and standard IMAP/POP configurations. Key features include rich-text formatting, customizable theming, flexible composition windows, read receipts, remote image controls, signatures, contact management, email archiving, spam filtering, focus mode, email filtering, and tracking element removal.
The Aerion email client has a clean, modern UI.
Screenshot by Jack Wallen/ZDNET
The user interface stands out as Aerion’s strongest advantage. The layout cleanly presents account panes, email lists, and viewing areas. Under Settings > General, users can customize the title bar style (Native, Aerion, or Disabled), select language preferences, and choose themes. I recommend the Native option, as Aerion’s additional title bar can feel redundant on Linux systems.
Focus Mode is helpful when you need to see only one email and nothing else.
Screenshot by Jack Wallen/ZDNET
Focus Mode deserves special mention—it transforms the interface to display only the currently viewed email. Activating this feature is as simple as clicking the small square icon near the top right, adjacent to the printer symbol.
Aerion handles multiple email accounts seamlessly, with account management available through the left sidebar. An “All Inboxes” view consolidates messages across accounts, eliminating the need to switch between individual inboxes.
Despite being in pre-release status, Aerion demonstrates impressive stability. macOS and Windows users can download installers directly from the official website, while Linux users can install via Flatpak from Flathub using the command: flatpak install --user io.github.hkdb.Aerion
Once installed, users can add their email accounts and begin using this polished, modern email client that successfully challenges established alternatives like Geary.
