# Gnus vs mu4e

- Gnus: Mail and news reader built into GNU Emacs, with back ends for IMAP, POP3, local mail folders and NNTP.
- mu4e: Email client that runs inside GNU Emacs, built on the mu Maildir indexer and search tool.

## Differences

- Only Gnus has built-in IMAP, POP3 and mbox.
- On Windows, Gnus runs natively and mu4e runs through WSL.
- Gnus is written in Emacs Lisp; mu4e in Emacs Lisp (mu4e), C++ (mu).
- Configuration: Gnus uses Emacs Lisp in init.el or ~/.gnus.el, and mu4e uses Emacs Lisp in init.el.

## Side by side

| | Gnus | mu4e |
| --- | --- | --- |
| Interface | Runs inside Emacs | Runs inside Emacs |
| Language | Emacs Lisp | Emacs Lisp (mu4e), C++ (mu) |
| License | GPL 3.0 or later | GPL 3.0 or later |
| Linux | Native | Native |
| macOS | Native | Native |
| Windows | Native | Through WSL |
| BSD | Native | Native |
| Android | Through Termux | Through Termux |
| IMAP | Yes | Through a separate tool |
| POP3 | Yes | Through a separate tool |
| SMTP | Yes | Yes |
| JMAP | No | No |
| Maildir | Yes | Yes |
| mbox | Yes | No |
| notmuch | Through a separate tool | No |
| OpenPGP | Yes | Yes |
| S/MIME | Yes | via Emacs MML |
| OAuth2 sign-in | via plugin | via script |
| Threads | Yes | Yes |
| Search | gnus-search: IMAP SEARCH, or notmuch, mu, mairix and other local indexers | Xapian full-text index with mu query syntax |
| HTML mail | built-in, rendered with the Emacs shr library | built-in, rendered with the Emacs shr library |
| Mouse | Yes | Yes |
| Multiple accounts | Yes | via contexts |
| Offline use | via the Gnus agent or local Maildir back ends | full; reads a local Maildir synced by mbsync or OfflineIMAP |
| Calendar | replies to invitations with gnus-icalendar | replies to invitations with mu4e-icalendar |
| Contacts | via BBDB or EUDC | address completion from indexed mail |
| Vim-style keys | No | No |
| Configuration | Emacs Lisp in init.el or ~/.gnus.el | Emacs Lisp in init.el |

Pages: [Gnus](https://terminalemail.com/clients/gnus/index.md), [mu4e](https://terminalemail.com/clients/mu4e/index.md)