Herald is a terminal-native email and calendar application that provides a GUI-like workspace inside a modern terminal. It combines inbox reading, composing, search, cleanup tools, contacts, calendar handling, and optional AI-assisted features, while still offering keyboard-first navigation, mouse support, demo mode, and integration surfaces for MCP and SSH workflows.
This is source-available software. It is not open source.
Key Features
- Supports standard IMAP, Gmail IMAP app passwords, Gmail OAuth, SMTP, and provider presets for services such as ProtonMail Bridge, Fastmail, iCloud, and Outlook.
- Includes a calendar workspace with Google Calendar OAuth, CalDAV support, event management, RSVP handling, and .ics import.
- Offers a terminal UI with keyboard shortcuts, clickable tabs, mouse scrolling, OSC 8 email links, context help, and theme inheritance from the terminal.
- Provides inbox cleanup features including sender and domain grouping, dry-run cleanup previews, archiving, deleting, hiding senders, and unsubscribe actions.
- Adds optional AI features for classification, semantic search, quick replies, chat, contact enrichment, and draft assistance using Ollama or external providers.
Website: github.com/herald-email/herald-mail-app
Support:
Developer: Herald Email
License: Functional Source License 1.1, ALv2 Future License

Herald is written in Go. Learn Go with our recommended free books and free tutorials.
Related Software
| Console Email Clients | |
|---|---|
| NeoMutt | Brings together many patches to extend Mutt |
| mu4e | An extension of mu that runs a full-featured email client within Emacs |
| Himalaya | CLI email client written in Rust |
| Sup | Curses threads-with tags style email client |
| Mutt | Small but very powerful text based program |
| Alpine | Alternatively Licensed Program for Internet News and Email |
| meli | Configurable and extensible e-mail client with sane defaults |
| nmail | User interface similar to alpine / pine |
| alot | Lets notmuch handle your mailindex and uses a toolkit to render its display |
| Wanderlust | Mail/news management system with IMAP4rev1 support for Emacs |
| aerc | Billed as a "pretty good email client" |
| matcha | Powerful, feature-rich email client for your terminal |
| Cone | COnsole Newsreader And Emailer |
| bower | Curses frontend for the Notmuch email system |
| Indicium Mail TUI | Keyboard-driven terminal interface with a streamlined workflow |
| CXPost | Cross-platform desktop app for managing multiple accounts |
| mxr | Local-first messaging app built for speed and offline use |
| Epist | Keyboard-centric desktop app for fast, focused correspondence |
| Vmail | Vim interface to Gmail |
| neatmail | Non-interactive email client |
Read our verdict in the software roundup.
LinuxLinks helps you discover the best free and open source software for Linux. Explore our extensive collection of recommended applications, including alternatives to popular proprietary software.We also publish software reviews, Linux tutorials, hardware reviews, free programming books and articles covering the wider open source community. Browse our Linux resources to discover more. Know a useful free and open source Linux application we haven't covered? Suggest a program for inclusion. Has your software been featured on LinuxLinks? Display one of our Featured on LinuxLinks badges on your website or GitHub README. |


Please read our Comment Policy before commenting.