Mailbird

Spark Mail

Spark Mail is an email client designed to simplify email management with AI-assisted email writing and smart inbox prioritization. It offers shared team inboxes for collaborative email management, making it an ideal solution for teams and individuals looking to streamline their email workflow.

BlueMail

BlueMail is a cross-platform email client from Blix that unifies multiple accounts into a single inbox across iOS, Android, macOS, Windows, and Linux. It groups incoming mail into Clusters to surface important messages, syncs settings across devices with MagicSync, and combines mail with an integrated calendar. The app includes GemAI, a generative AI layer that can summarize threads, draft replies, and translate messages while trying to preserve the sender's tone. Security-conscious users get end-to-end PGP and S/MIME encryption with self-managed keys, and teams can move up to paid Plus, Team, or Enterprise tiers for AI usage limits, custom domain mailboxes, and SSO/MDM support.

eM Client

eM Client is a desktop email application for Windows and macOS (with companion Android/iOS apps) positioned as an alternative to Outlook and Thunderbird. It bundles email, calendar, tasks, notes, and chat into one interface, with inbox categorization, quick actions, and an AI add-on for drafting and summarizing. The free tier covers up to two accounts for personal, non-commercial use, while paid Personal and Business licenses remove that account limit and unlock features like PGP message encryption, snooze, translation, and mass mail tools. Licenses are available as annual subscriptions or one-time lifetime purchases, and mobile apps are free without a separate license.

Thunderbird

Thunderbird is a free and open-source desktop email client developed by the Mozilla-backed Thunderbird project, combining email, calendar, and contacts management in one cross-platform application. It supports a unified view across multiple accounts, tagging and advanced filters, and an extensive add-on ecosystem for customization. Funded primarily by user donations rather than ads or data collection, Thunderbird is positioned for privacy-conscious users and organizations who want to own their email experience. It runs on Windows, macOS, and Linux, with an official Android app available through Google Play and F-Droid.

Mailspring

Mailspring is a native desktop email client from independent studio Foundry376, built for Mac, Windows, and Linux. It unifies accounts from Gmail, iCloud, Office 365, Outlook.com, Yahoo, FastMail, and generic IMAP/SMTP providers into one fast, searchable inbox with Gmail-style search syntax. Its free tier covers core mail management, while the $8/month Pro plan adds read receipts, link tracking, send-later scheduling, follow-up reminders, templates, and contact enrichment (with limited weekly trials of Pro features in the free app). The client emphasizes native platform integration, including Windows taskbar badges, macOS notifications, and Linux system tray support.