Your Guide to Aerion: Setting Up a Secure, Lightweight Desktop Email Client

Introduction

If you manage multiple email accounts daily, a dedicated desktop client can streamline your workflow. Aerion is an open‑source, resource‑efficient email client built for Linux. It carries a CASA Tier 2 security certification (verified by TAC Security under Google’s App Defense Alliance) and offers a clean interface without the bloat of older solutions. This guide walks you through installing, configuring, and getting the most out of Aerion.

What You Need

• A supported Linux distribution (e.g., Ubuntu, Fedora, Debian)
• An active internet connection
• At least one email account (supports Gmail, Microsoft 365/Outlook, Proton Mail via Proton Bridge, iCloud Mail, GMX Mail, and generic IMAP/SMTP)
• A modern web browser (for the OAuth authentication flow)
• (Optional) Proton Bridge subscription if you use Proton Mail

Step‑by‑Step Setup

Step 1: Download and Install Aerion

Head over to the official Aerion website (or its GitHub releases page) and download the appropriate package for your Linux distribution – typically a .AppImage, .deb, or .rpm file. Make the file executable if needed, then run it. The installation process is straightforward and should place Aerion in your applications menu.

Step 2: Launch the Application

Open Aerion from your desktop launcher. On first launch, you’ll be greeted by a clean, minimal interface. The main window displays an empty inbox area and an Add Email Account button. Click that button to begin the configuration.

Step 3: Add Your First Email Account (Gmail Example)

Click Add Email Account. A small dialog appears. Choose Gmail from the list of supported providers. Aerion will immediately launch your default web browser for the OAuth authorization flow.

Step 4: Complete OAuth Authentication

In the browser, sign in to your Google account and grant the requested permissions. After you approve, Google redirects you back to Aerion, and the app automatically completes the authentication. You’ll see your inbox populate with messages, and the account is now active.

Step 5: Avoid the Dismiss‑Without‑Warning Pitfall

One important catch: while the Add Email Account dialog is open, clicking anywhere outside that small window will silently close it, discarding all progress. There is no warning or confirmation prompt. To avoid frustration, make sure you complete the entire OAuth flow without clicking outside that dialog. If you accidentally close it, simply click Add Email Account again and redo the authentication.

Step 6: Customise Your Experience

Once an account is set up, you can explore Aerion’s features:

• Switch between multiple color themes via the Settings menu.
• Enable conversation threading to group related emails.
• Use the WYSIWYG composer (powered by TipTap) for rich text formatting.
• Sync your contacts from CardDAV, Google, or Microsoft accounts.
• Activate keyboard navigation with vim‑style shortcuts for faster operation.

Step 7: Add Additional Accounts

To manage more inboxes, repeat Steps 3–5 for each provider. Aerion supports Gmail, Microsoft 365/Outlook, Proton Mail (via the paid Proton Bridge), iCloud Mail, GMX Mail, and any generic IMAP/SMTP setup. Note that Yahoo, Fastmail, Zoho Mail, AOL Mail, and Mail.com are listed but marked as untested at the time of writing – proceed with caution.

Tips for a Smooth Experience

• Keep it secure: Aerion’s CASA Tier 2 certification means its code has been independently audited against OWASP ASVS standards. Still, always use strong passwords and enable two‑factor authentication on your email accounts.
• Beware of the OAuth window trap: Always stay focused on the small “Add Email Account” dialog until you finish an OAuth flow – clicking outside will erase your progress.
• Test generic IMAP/SMTP carefully: If you use a less common provider, configure it manually. Aerion may work, but because it is pre‑release software, you might encounter glitches.
• Take advantage of keyboard shortcuts: Learn the vim‑style navigation (e.g., j/k to move between messages) to work through your inbox much faster.
• Consider Proton Bridge for Proton Mail: Proton Mail integration requires a paid Bridge subscription. Weigh the cost against the convenience of having all your mail in one place.
• Back up your configuration: Since Aerion is still in development, periodically export your settings (if available) or manually note your account details so you can quickly restore your setup after an update.

With these steps and tips, you can start using Aerion as a secure, lightweight hub for all your email accounts. Give it a try and see how it transforms your daily messaging routine.