This post was heavily inspired by Email setup in Emacs with Mu4e on macOS, but with my own tweaks for a single-account configuration and some Doom-specific configurations.

Overview

Mu4e is an Emacs-based email client based on mu, an indexer that stores email in the Maildir format.

This blog post covers the installation of Mu4e in Doom Emacs on macOS. This guide should be very similar to GNU Emacs and Linux-based systems, with a few tweaks required in the various configuration files.

Installation

Prerequisites

Create the Folder Structure

Start by creating the base folder structure:

mkdir ~/.maildir
mkdir ~/.maildir/example      # use whatever name you want to call your email account
mkdir ~/.maildir/certificates # used to store system root certificates

Store Email Account Passwords in macOS Keychain

Next, I will be using the macOS Keychain to store my email account passwords using the command below.

security add-generic-password -s mu4e-example -a [email protected] -w

This will prompt you to input your password twice to confirm. Keep the mu4e-example name in mind, as you will need to reference it later in the IMAP and SMTP configuration files.

Store Root Certificates

In order to use IMAP and SMTP, we need to provide certificates to the local services. We will use the macOS defaults for this.

1. Open Keychain Access.app.
2. Select System Roots in the sidebar.
3. Select all items with CMD + a.
4. Export selected items with SHIFT + CMD + a to the file ~/.maildir/certificates/root-certificates.pem.

Install Dependencies

Install mbsync (via isync) to fetch emails via IMAP, mu to index emails, and msmtp to send emails via SMTP.

brew install mu isync msmtp

Installing Mu4e

Within Doom Emacs, we can install Mu4e by enabling the package.

nano ~/.doom.d/init.el

In this file, uncomment the mu4e line within the :email section. You can also enable the +org and +gmail options if you prefer.

(doom! :input
       ...
       :email
       mu4e
       ;;(mu4e +org +gmail)
       ...
       (default +bindings +smartparens))

Configuration

As an overall suggestion, I create the following configuration files in the ~/.maildir directory and using symlinks to their proper locations so that I can backup and restore these files easily.

touch ~/.maildir/.mbsyncrc && \
touch ~/.maildir/.msmtprc  && \
ln -s /Users/username/.maildir/.mbsyncrc /Users/username/.mbsyncrc && \
ln -s /Users/username/.maildir/.msmtprc /Users/username/.msmtprc

You can also create these files in your home directory and skip the symlinking process above.

IMAP

Next, let's configure mbsync in the file created above. Paste the following information and customize it to match your mail provider's information.

nano ~/.maildir/.mbsyncrc

IMAPAccount example
Host imap.example.com
User dummy@example.com
PassCmd "security find-generic-password -s mu4e-example -a [email protected] -w"
Port 993
SSLType IMAPS
AuthMechs Login
CertificateFile ~/.maildir/certificates/root-certificates.pem

IMAPStore example-remote
Account example

MaildirStore example-local
SubFolders Verbatim
Path ~/.maildir/example/
Inbox ~/.maildir/example/INBOX

Channel example
Far :example-remote:
Near :example-local:
Patterns *
Create Near
Sync All
Expunge Both
SyncState *

SMTP

Next, let's configured msmtprc in the file created above. Paste the following information and customize it to match your mail provider's information.

nano ~/.maildir/.msmtprc

# Set default values for all the accounts.
defaults
logfile ~/.maildir/msmtp.log
tls_trust_file ~/.maildir/certificates/root-certificates.pem

# ======================================================================

account startmail
auth on
host smtp.startmail.com
port 465
protocol smtp
from hello@cleberg.net
user hello@cleberg.net
passwordeval security find-generic-password -s startmail -a hello@cleberg.net -w
tls on
tls_starttls off

# ======================================================================

account default : startmail

Doom Emacs

Finally, we need to configure Doom Emacs to use the proper packages and set some variables and functions.

nano ~/.doom.d/config.el

;; load packages and programs
(use-package mu4e
  :load-path  "/Users/username/.emacs.d/modules/email/mu4e/")
(require 'smtpmail)
(setq mu4e-mu-binary (executable-find "mu"))

;; set base directory
(setq mu4e-maildir "~/.maildir")

;; sync imap servers
(setq mu4e-get-mail-command (concat (executable-find "mbsync") " -a"))

;; how often to sync in seconds
(setq mu4e-update-interval 300)

;; save attachments to defined directory
(setq mu4e-attachment-dir "~/Downloads")

;; rename files when moving - needed for mbsync:
(setq mu4e-change-filenames-when-moving t)

;; list of your email adresses:
(setq mu4e-user-mail-address-list '("[email protected]"))

;; check your ~/.maildir to see naming of subdirectories
(setq   mu4e-maildir-shortcuts
        '(("/example/INBOX" . ?e)
          ("/example/Sent" . ?E)))

(setq mu4e-contexts
      `(,(make-mu4e-context
          :name "example"
          :enter-func
          (lambda () (mu4e-message "Enter [email protected] context"))
          :leave-func
          (lambda () (mu4e-message "Leave [email protected] context"))
          :match-func
          (lambda (msg)
            (when msg
              (mu4e-message-contact-field-matches msg
                                                  :to "[email protected]")))
          :vars '((user-mail-address . "[email protected]")
                  (user-full-name . "Christian Cleberg")
                  ;; check your ~/.maildir to see how the subdirectories are called
                  ;; e.g `ls ~/.maildir/example'
                  (mu4e-drafts-folder . "/example/Drafts")
                  (mu4e-refile-folder . "/example/Archive")
                  (mu4e-sent-folder . "/example/Sent")
                  (mu4e-trash-folder . "/example/Trash")))))

(setq mu4e-context-policy 'pick-first) ;; start with the first (default) context;
(setq mu4e-compose-context-policy 'ask) ;; ask for context if no context matches;

;; gpg encryptiom & decryption:
;; this can be left alone
(require 'epa-file)
(epa-file-enable)
(setq epa-pinentry-mode 'loopback)
(auth-source-forget-all-cached)

;; don't keep message compose buffers around after sending:
(setq message-kill-buffer-on-exit t)

;; send function:
(setq send-mail-function 'sendmail-send-it
      message-send-mail-function 'sendmail-send-it)

;; send program:
(setq sendmail-program (executable-find "msmtp"))

;; select the right sender email from the context.
(setq message-sendmail-envelope-from 'header)

;; mu4e cc & bcc
(add-hook 'mu4e-compose-mode-hook
          (defun timu/add-cc-and-bcc ()
            "My Function to automatically add Cc & Bcc: headers.
    This is in the mu4e compose mode."
            (save-excursion (message-add-header "Cc:\n"))
            (save-excursion (message-add-header "Bcc:\n"))))

;; mu4e address completion
(add-hook 'mu4e-compose-mode-hook 'company-mode)

Be sure to sync Doom to update the current configurations.

doom sync

If you have Doom open, execute SPC h r r to reload the new configurations.

Initial Sync

Once you have configured all of the relevant files, you can perform an initial sync. Note that you can perform syncing within Mu4e itself afer this.

mbsync -aV

Once you sync the data, you can index the emails.

mu init -m ~/.maildir --my-address [email protected] && \
mu index

The emails will now to be ready to use!

Screenshots

You can now launch Doom and open Mu4e with SPC o m. You can also explore the Mu4e options with SPC : mu4e.

The home page shows various options and metdata about the account you've opened.

When composing an email, you can see the metadata fields at the top and compose the message below the indicator line.

When in a folder, you can view emails in a pane and perform actions as needed.