# aerc vs mu4e

- aerc: Terminal email client written in Go with IMAP, JMAP, Maildir and notmuch backends and an embedded terminal for editing.
- mu4e: Email client that runs inside GNU Emacs, built on the mu Maildir indexer and search tool.

## Differences

- aerc is a full-screen terminal client; mu4e is a mail client that runs inside Emacs.
- Only aerc has built-in IMAP, JMAP, mbox and notmuch.
- mu4e has S/MIME; aerc does not.
- aerc has Vim-style keys; mu4e does not.
- aerc is written in Go; mu4e in Emacs Lisp (mu4e), C++ (mu).
- Configuration: aerc uses INI-style files: accounts.conf, aerc.conf, binds.conf, and mu4e uses Emacs Lisp in init.el.

## Side by side

| | aerc | mu4e |
| --- | --- | --- |
| Interface | Full-screen terminal interface | Runs inside Emacs |
| Language | Go | Emacs Lisp (mu4e), C++ (mu) |
| License | MIT | 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 | Yes | Through a separate tool |
| POP3 | No | Through a separate tool |
| SMTP | Yes | Yes |
| JMAP | Yes | No |
| Maildir | Yes | Yes |
| mbox | Yes | No |
| notmuch | Yes | No |
| OpenPGP | Yes | Yes |
| S/MIME | No | via Emacs MML |
| OAuth2 sign-in | Yes | via script |
| Threads | Yes | Yes |
| Search | built-in; server-side for IMAP and JMAP; notmuch queries | Xapian full-text index with mu query syntax |
| HTML mail | via filters, w3m by default | built-in, rendered with the Emacs shr library |
| Mouse | Yes | Yes |
| Multiple accounts | Yes | via contexts |
| Offline use | with mbsync or OfflineIMAP through the Maildir backend; IMAP header cache | full; reads a local Maildir synced by mbsync or OfflineIMAP |
| Calendar | Yes | replies to invitations with mu4e-icalendar |
| Contacts | via address-book-cmd, e.g. khard or the bundled carddav-query | address completion from indexed mail |
| Vim-style keys | Yes | No |
| Configuration | INI-style files: accounts.conf, aerc.conf, binds.conf | Emacs Lisp in init.el |

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