Exploring Aerion: A Modern Desktop Email Client Worth Your Time

Desktop email clients have come a long way since the days of Thunderbird. If you manage multiple inboxes, a dedicated app can streamline your workflow without the constant tab-switching of webmail. After years of relying on browser-based email, I decided to give desktop clients another try—and I stumbled upon Aerion, an open-source contender that impressed me with its lightweight design and security focus. Below, I answer common questions about this new app to help you decide if it's right for you.

What Is Aerion and Who Is It For?

Aerion is an open-source, lightweight desktop email client maintained by a team sponsored by 3DF (which covers infrastructure and HR costs). It draws inspiration from GNOME's Geary, emphasizing resource efficiency and a clean interface—free from the bloat that plagues older Linux solutions. Unlike many modern apps, Aerion avoids Electron; it uses Wails and Svelte under the hood. This makes it ideal for users who need a fast, minimalist client that respects system resources. It's perfect for anyone juggling multiple accounts—Gmail, Microsoft 365, Proton Mail (via paid Bridge), iCloud, GMX, and generic IMAP/SMTP—and wants a unified inbox without the overhead of webmail tabs. However, note that Aerion is pre-release software, so occasional bugs may occur.

How Secure Is Aerion for Handling My Email Credentials?

Security is a top priority for Aerion. It holds a CASA Tier 2 certification, assessed by TAC Security (a Google-authorized assessor under the App Defense Alliance). This means the codebase was independently scanned and verified against OWASP ASVS standards. For a small indie project, this third-party validation provides peace of mind when handling sensitive login data. Additionally, Aerion uses OAuth for services like Gmail, so your credentials never touch the app directly—you authenticate through your browser's secure flow. While no software is perfect, Aerion's transparency and certification make it a trustworthy choice for privacy-conscious users.

What Key Features Does Aerion Offer?

Aerion covers all the essentials and then some. Key features include:

• Multiple account support with conversation threading.
• A WYSIWYG composer powered by TipTap for rich email formatting.
• Contact sync via CardDAV, Google, and Microsoft.
• Multiple color themes to personalize your workspace.
• Keyboard navigation with vim-style shortcuts for power users.
• Compatibility with Gmail, Microsoft 365/Outlook, Proton Mail (via Proton Bridge), iCloud Mail, GMX Mail, and generic IMAP/SMTP. Yahoo, Fastmail, Zoho Mail, AOL, and Mail.com are listed but untested.

Overall, it balances simplicity with functionality, avoiding the clutter of older clients.

How Does the Setup Process Work?

Setting up Aerion is surprisingly smooth—at least for Gmail. When you add an account, the app redirects you to your browser for the OAuth flow. You'll go through Google's standard permissions and then land back in Aerion, fully authenticated and ready to go. It's nearly seamless. However, there's a notable catch: if you accidentally click outside the "Add Email Account" window while it's open, the entire process cancels without warning—no confirmation dialog, no save point. That can be frustrating, so be careful to keep the window focused during account setup. Once added, email fetching begins automatically, and your inbox populates quickly.

What Are the Main Pros and Cons Compared to Webmail?

Pros:

• Unified inbox for multiple accounts without browser tabs.
• Lightweight and resource-efficient (no Electron bloat).
• Strong security certification (CASA Tier 2).
• Keyboard shortcuts and themes for power users.

Cons:

• Pre-release software; bugs and incomplete features possible.
• Account setup window is fragile—clicking outside cancels without warning.
• Some email providers (Yahoo, Fastmail, etc.) listed as untested.
• Limited advanced features like complex filtering or rules.

Overall, if you value speed and security over advanced automation, Aerion is worth a try.

Should You Give Aerion a Try?

If you're tired of webmail tabs eating RAM and want a dedicated client that's secure and modern, Aerion is an excellent candidate. Its open-source nature and independent security audit set it apart from many indie projects. The setup is easy for popular services, and the interface is clean. Just keep in mind it's pre-release, so occasional hiccups are normal. For a lightweight, privacy-respecting email client that doesn't sacrifice essential features, Aerion delivers. I recommend testing it alongside your current workflow to see if it fits your needs.