Add email support with notmuch, mbsync, and msmtp

Set up complete email workflow in Emacs using:
- notmuch for email indexing and UI
- mbsync for IMAP synchronization from proton.johnogle.info
- msmtp for SMTP sending via port 25 with PLAIN auth
- systemd timer for automatic sync every 5 minutes

Configuration includes:
- New email role at home/roles/email with all mail tools
- Doom Emacs notmuch module enabled with saved searches
- Secure credential retrieval via rbw from Bitwarden
- Fixed systemd service PATH to access rbw-agent
- TLS/STARTTLS for secure connections

Email role enabled on nix-book (laptop-compact profile).

home/roles/default.nix

@@ -8,6 +8,7 @@
     ./communication
     ./desktop
     ./development
+    ./email
     ./gaming
     ./kdeconnect
     ./kubectl

home/roles/emacs/doom/config.el

@@ -159,6 +159,32 @@
   (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"
+
+        ;; User identity
+        user-mail-address "john@ogle.fyi"
+        user-full-name "John Ogle"
+
+        ;; Sending mail via msmtp
+        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"))))
+
 ;; 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.
 ;;

home/roles/emacs/doom/init.el

@@ -177,7 +177,7 @@
 
        :email
        ;;(mu4e +org +gmail)
-       ;;notmuch
+       notmuch
        ;;(wanderlust +gmail)
 
        :app

home/roles/email/default.nix

@@ -0,0 +1,128 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  cfg = config.home.roles.email;
+in
+{
+  options.home.roles.email = {
+    enable = mkEnableOption "Enable email with notmuch, mbsync, and msmtp";
+  };
+
+  config = mkIf cfg.enable {
+    home.packages = with pkgs; [
+      isync      # provides mbsync for IMAP sync
+      msmtp      # for SMTP sending
+      notmuch    # email indexing and search
+      openssl    # for certificate management
+    ];
+
+    # Ensure Mail directory exists
+    home.file."Mail/.keep".text = "";
+
+    # mbsync configuration
+    home.file.".mbsyncrc".text = ''
+      # IMAP Account Configuration
+      IMAPAccount proton
+      Host proton.johnogle.info
+      Port 143
+      User john@ogle.fyi
+      PassCmd "${pkgs.rbw}/bin/rbw get proton.johnogle.info"
+      TLSType STARTTLS
+      AuthMechs PLAIN
+
+      # Remote Storage
+      IMAPStore proton-remote
+      Account proton
+
+      # Local Storage
+      MaildirStore proton-local
+      Path ~/Mail/
+      Inbox ~/Mail/INBOX
+      SubFolders Verbatim
+
+      # Channel Configuration - Sync All
+      Channel proton
+      Far :proton-remote:
+      Near :proton-local:
+      Patterns *
+      Create Both
+      Expunge Both
+      SyncState *
+    '';
+
+    # Notmuch configuration
+    home.file.".notmuch-config".text = ''
+      [database]
+      path=${config.home.homeDirectory}/Mail
+
+      [user]
+      name=John Ogle
+      primary_email=john@ogle.fyi
+
+      [new]
+      tags=unread;inbox;
+      ignore=
+
+      [search]
+      exclude_tags=deleted;spam;
+
+      [maildir]
+      synchronize_flags=true
+    '';
+
+    # msmtp configuration
+    home.file.".msmtprc".text = ''
+      # Default settings
+      defaults
+      auth           plain
+      tls            on
+      tls_starttls   on
+      tls_trust_file /etc/ssl/certs/ca-certificates.crt
+      logfile        ${config.home.homeDirectory}/.msmtp.log
+
+      # Proton mail account
+      account        proton
+      host           proton.johnogle.info
+      port           25
+      from           john@ogle.fyi
+      user           john@ogle.fyi
+      passwordeval   rbw get proton.johnogle.info
+
+      # Set default account
+      account default : proton
+    '';
+
+    # Systemd service for mail sync
+    systemd.user.services.mbsync = {
+      Unit = {
+        Description = "Mailbox synchronization service";
+        After = [ "network-online.target" ];
+        Wants = [ "network-online.target" ];
+      };
+      Service = {
+        Type = "oneshot";
+        ExecStart = "${pkgs.bash}/bin/bash -c '${pkgs.isync}/bin/mbsync -a && ${pkgs.notmuch}/bin/notmuch new'";
+        Environment = "PATH=${pkgs.rbw}/bin:${pkgs.coreutils}/bin";
+        StandardOutput = "journal";
+        StandardError = "journal";
+      };
+    };
+
+    # Systemd timer for automatic sync
+    systemd.user.timers.mbsync = {
+      Unit = {
+        Description = "Mailbox synchronization timer";
+      };
+      Timer = {
+        OnBootSec = "2min";
+        OnUnitActiveSec = "5min";
+        Unit = "mbsync.service";
+      };
+      Install = {
+        WantedBy = [ "timers.target" ];
+      };
+    };
+  };
+}