# mu4e vs Notmuch Emacs interface

- mu4e: Email client that runs inside GNU Emacs, built on the mu Maildir indexer and search tool.
- Notmuch Emacs interface: Emacs front end for notmuch that reads, searches, tags and composes mail from a local Maildir.

## Differences

- Only Notmuch Emacs interface has built-in notmuch.
- mu4e is written in Emacs Lisp (mu4e), C++ (mu); Notmuch Emacs interface in Emacs Lisp.
- Configuration: mu4e uses Emacs Lisp in init.el, and Notmuch Emacs interface uses Emacs Lisp in init.el plus the notmuch config file.

## Side by side

| | mu4e | Notmuch Emacs interface |
| --- | --- | --- |
| Interface | Runs inside Emacs | Runs inside Emacs |
| Language | Emacs Lisp (mu4e), C++ (mu) | Emacs Lisp |
| License | GPL 3.0 or later | GPL 3.0 or later |
| Linux | Native | Native |
| macOS | Native | Native |
| Windows | Through WSL | Through WSL |
| BSD | Native | Native |
| Android | Through Termux | Through Termux |
| IMAP | Through a separate tool | Through a separate tool |
| POP3 | Through a separate tool | Through a separate tool |
| SMTP | Yes | Yes |
| JMAP | No | No |
| Maildir | Yes | Yes |
| mbox | No | No |
| notmuch | No | Yes |
| OpenPGP | Yes | Yes |
| S/MIME | via Emacs MML | Yes |
| OAuth2 sign-in | via script | via script |
| Threads | Yes | Yes |
| Search | Xapian full-text index with mu query syntax | notmuch Xapian full-text search with tags |
| HTML mail | built-in, rendered with the Emacs shr library | built-in, rendered with the Emacs shr library |
| Mouse | Yes | Yes |
| Multiple accounts | via contexts | Yes |
| Offline use | full; reads a local Maildir synced by mbsync or OfflineIMAP | full; reads a local Maildir synced by mbsync or OfflineIMAP |
| Calendar | replies to invitations with mu4e-icalendar | shows text/calendar parts; no invitation replies |
| Contacts | address completion from indexed mail | address completion from the notmuch index |
| Vim-style keys | No | No |
| Configuration | Emacs Lisp in init.el | Emacs Lisp in init.el plus the notmuch config file |

Pages: [mu4e](https://terminalemail.com/clients/mu4e/index.md), [Notmuch Emacs interface](https://terminalemail.com/clients/notmuch-emacs/index.md)