Replace notmuch with mu4e for email

mu4e's refile moves messages between IMAP folders, enabling
cross-device sync via mbsync. notmuch tags are local-only.

- Switch from notmuch to mu/mu4e packages
- Auto-initialize mu database on first sync
- Configure mu4e with folder shortcuts and refile to Archive
- Add NixOS load-path for mu4e elisp files

home/roles/emacs/doom/config.el

@@ -159,31 +159,48 @@
   (dolist (module '("bbdb" "buffer" "elisp" "emacs" "gnus" "os" "search-and-replace" "url"))
     (gptel-tool-library-load-module module)))
 
-;; Notmuch email configuration
-(after! notmuch
-  (setq notmuch-search-oldest-first nil
-        notmuch-show-logo nil
-        notmuch-fcc-dirs "proton/Sent"
+;; mu4e email configuration
+;; Add NixOS mu4e to load-path (installed via mu.mu4e package)
+(when-let ((mu-path (executable-find "mu")))
+  (add-to-list 'load-path
+               (expand-file-name "../share/emacs/site-lisp/mu4e"
+                                 (file-name-directory mu-path))))
 
-        ;; User identity
-        user-mail-address "john@ogle.fyi"
-        user-full-name "John Ogle"
+(after! mu4e
+  ;; User identity
+  (setq user-mail-address "john@ogle.fyi"
+        user-full-name "John Ogle")
 
-        ;; Sending mail via msmtp
-        message-send-mail-function 'message-send-mail-with-sendmail
+  ;; Maildir location (no account prefix - single account)
+  (setq mu4e-maildir "~/Mail"
+        mu4e-attachment-dir "~/Downloads")
+
+  ;; Folder config (matches ~/Mail/INBOX, ~/Mail/Sent, etc.)
+  (setq mu4e-sent-folder "/Sent"
+        mu4e-drafts-folder "/Drafts"
+        mu4e-trash-folder "/Trash"
+        mu4e-refile-folder "/Archive")
+
+  ;; Shortcuts for common folders
+  (setq mu4e-maildir-shortcuts
+        '((:maildir "/INBOX"   :key ?i)
+          (:maildir "/Archive" :key ?a)
+          (:maildir "/Sent"    :key ?s)
+          (:maildir "/Trash"   :key ?t)))
+
+  ;; Behavior settings
+  (setq mu4e-get-mail-command "mbsync -a"
+        mu4e-update-interval 300  ; 5 minutes (matches systemd timer)
+        mu4e-change-filenames-when-moving t  ; required for mbsync
+        mu4e-headers-date-format "%Y-%m-%d"
+        mu4e-headers-time-format "%H:%M")
+
+  ;; Sending mail via msmtp
+  (setq message-send-mail-function 'message-send-mail-with-sendmail
         sendmail-program (executable-find "msmtp")
         message-sendmail-envelope-from 'header
         mail-envelope-from 'header
-        mail-specify-envelope-from t
-
-        ;; Saved searches for quick access
-        notmuch-saved-searches
-        '((:name "inbox"   :query "tag:inbox"                    :key "i")
-          (:name "unread"  :query "tag:unread"                   :key "u")
-          (:name "flagged" :query "tag:flagged"                  :key "f")
-          (:name "sent"    :query "tag:sent"                     :key "t")
-          (:name "drafts"  :query "tag:draft"                    :key "d")
-          (:name "all"     :query "*"                            :key "a"))))
+        mail-specify-envelope-from t))
 
 ;; Whenever you reconfigure a package, make sure to wrap your config in an
 ;; `after!' block, otherwise Doom's defaults may override your settings. E.g.