# Alternatives to Postbox Power-user desktop mail (acquired by eM Client). Postbox ranks #16 of 22 in Email clients, with an Alt Score of 63. It is proprietary, sold as a one-time purchase and available on macOS and Windows. 7 of 11 checklist rows are verified against a public source. Source: https://altcatalog.com/alternatives/postbox/ Category: Email clients ## Overview - **Who it's for**: Mac and Windows users who managed multiple email accounts and wanted an advanced native desktop client rather than webmail — often power users migrating from Thunderbird or Apple Mail. - **What you get**: A single desktop inbox consolidating several email accounts, with keyboard-driven Quick Bar actions, extensive filtering and rules, drag-and-drop organization, and a customizable interface with a built-in theme editor. Postbox was acquired by eM Client, and standalone development has since wound down, with the vendor directing users to eM Client for continued support. - **How it works**: Users connected their email accounts to the desktop app, then read, filtered, tagged, and organized messages through customizable panels and keyboard shortcuts rather than a browser-based webmail interface. ## Profile - **License**: Proprietary (verified 2026-07-12) - **Pricing model**: One-time (verified 2026-07-12) - **Starts at**: ? - **Platforms**: macOS, Windows - **Status**: acquired (verified 2026-07-12) ## Ranked alternatives | # | App | Alt Score | Licence | Platforms | |---|-----|-----------|---------|-----------| | 1 | [eM Client](https://altcatalog.com/alternatives/em-client.md) | 96 | Proprietary | Windows, macOS, iOS, Android | | 2 | [BlueMail](https://altcatalog.com/alternatives/bluemail.md) | 92 | Proprietary | Windows, macOS, Linux, iOS | | 3 | [Canary Mail](https://altcatalog.com/alternatives/canary-mail.md) | 92 | Proprietary | Windows, macOS, iOS, Android | | 4 | [The Bat!](https://altcatalog.com/alternatives/the-bat.md) | 92 | Proprietary | Windows | | 5 | [Apple Mail](https://altcatalog.com/alternatives/apple-mail.md) | 87 | Proprietary | macOS, iOS | | 6 | [FairEmail](https://altcatalog.com/alternatives/fairemail.md) | 87 | GPL-3.0 | Android | | 7 | [Mailbird](https://altcatalog.com/alternatives/mailbird.md) | 87 | Proprietary | Windows, macOS | | 8 | [Evolution](https://altcatalog.com/alternatives/evolution.md) | 84 | LGPL-2.1 | Linux | | 9 | [Mailspring](https://altcatalog.com/alternatives/mailspring.md) | 84 | GPL-3.0 | Windows, macOS, Linux | | 10 | [Missive](https://altcatalog.com/alternatives/missive.md) | 84 | Proprietary | Web, Windows, macOS, iOS | | 11 | [Outlook](https://altcatalog.com/alternatives/outlook.md) | 84 | Proprietary | Windows, macOS, iOS, Android | | 12 | [Thunderbird](https://altcatalog.com/alternatives/thunderbird.md) | 76 | MPL-2.0 | Windows, macOS, Linux | | 13 | [Spark](https://altcatalog.com/alternatives/spark.md) | 71 | Proprietary | Windows, macOS, iOS, Android | | 14 | [NeoMutt](https://altcatalog.com/alternatives/neomutt.md) | 68 | GPL-2.0 | Linux, macOS | | 15 | [Shortwave](https://altcatalog.com/alternatives/shortwave.md) | 68 | Proprietary | Web, macOS, Windows, iOS | | 16 | [Mimestream](https://altcatalog.com/alternatives/mimestream.md) | 60 | Proprietary | macOS | | 17 | [Aqua Mail](https://altcatalog.com/alternatives/aqua-mail.md) | 55 | Proprietary | Android | | 18 | [Superhuman](https://altcatalog.com/alternatives/superhuman.md) | 55 | Proprietary | Windows, macOS, iOS, Android | | 19 | [Geary](https://altcatalog.com/alternatives/geary.md) | 50 | LGPL-2.1-or-later | Linux | | 20 | [K-9 Mail](https://altcatalog.com/alternatives/k-9-mail.md) | 47 | Apache-2.0 | Android | | 21 | [aerc](https://altcatalog.com/alternatives/aerc.md) | 42 | MIT | Linux, macOS | Alt Score = Verified coverage (90%) + Visibility (10%). See https://altcatalog.com/how-alt-score-works/ ## Feature comparison Legend: Yes / No / Partial / ? (not verified). | Email clients checklist | Postbox | eM Client | BlueMail | Canary Mail | The Bat! | Apple Mail | |---|---|---|---|---|---|---| | Pricing model | One-time | Freemium | Freemium | Freemium | One-time | Free | | Starts at | ? | €39.95/year | ? | $3/month | €47.95 one-time (Home Edition) | ? | | License | Proprietary | Proprietary | Proprietary | Proprietary | Proprietary | Proprietary | | Platforms | macOS, Windows | Windows, macOS, iOS, Android | Windows, macOS, Linux, iOS, Android, Web | Windows, macOS, iOS, Android | Windows | macOS, iOS | | Protocols (IMAP / POP3 / JMAP / Exchange) | Yes | Yes | Yes | Partial | Yes | Yes | | Unified inbox | Yes | Yes | Yes | Yes | Yes | Yes | | Snooze & send later | ? | Yes | Yes | Yes | Partial | Yes | | Tracking pixel blocking | Yes | Yes | Yes | Yes | Yes | Yes | | PGP / encryption support | ? | Yes | Yes | Yes | Yes | Partial | | Conversation view | Yes | Yes | Yes | Yes | Yes | Yes | | Offline mode | ? | Yes | Yes | Yes | Yes | Yes | | Rules & filters (local) | Yes | Yes | Partial | Yes | Yes | Yes | | Calendar integrated | ? | Yes | Yes | Yes | Yes | Partial | | Multiple identities/aliases | Yes | Yes | Yes | Yes | Yes | Yes | | Keyboard-first shortcuts | Partial | Partial | Partial | Partial | Partial | Partial | ## Sources Sources for Postbox. Each alternative is sourced on its own page. - **Pricing model**: One-time — (verified 2026-07-12) - Quote: “Enter the email address used to purchase Postbox below:” - **Platforms**: macOS, Windows — (verified 2026-07-12) - Quote: “macOS 10.13 through 15 / Windows 8 through 11” - **License**: Proprietary — (verified 2026-07-12) - Quote: “Licensee shall not, nor permit anyone else to, directly or indirectly: (i) copy (except for a reasonable number of backup copies), modify, or distribute the Software” - **Status**: acquired — (verified 2026-07-12) - Quote: “Postbox has been acquired by eM Client and is no longer in development or available for purchase.” - **Protocols (IMAP / POP3 / JMAP / Exchange)**: Yes — (verified 2026-07-12) - Quote: “Postbox supports IMAP, POP3, and SMTP servers” - **Unified inbox**: Yes — (verified 2026-07-12) - Quote: “Create separate groups to hold your 'personal' and 'work' accounts, then unify them into one view.” - **Tracking pixel blocking**: Yes — (verified 2026-07-12) - Quote: “Use Anti-Tracking to prevent pesky salespeople from knowing if and when you open a message.” - **Conversation view**: Yes — (verified 2026-07-12) - Quote: “Postbox gathers message fragments from multiple folders and presents them in a unified view” - **Rules & filters (local)**: Yes — (verified 2026-07-12) - Quote: “Postbox provides the most complete filtering rule sets on the market” - **Multiple identities/aliases**: Yes — (verified 2026-07-12) - Quote: “You can use identities (also known as 'aliases') to prevent junk mail from being sent to your primary email addresses.” - **Keyboard-first shortcuts**: Partial — (verified 2026-07-12) - Quote: “For our power users, Postbox supports a full suite of keyboard shortcuts.” --- Ranked by verified data, never by who paid. https://altcatalog.com/trust/