home: mail: add msmtp

home/mail/default.nix

@@ -1,9 +1,23 @@
 { config, lib, ... }:
+let
+  cfg = config.my.home.mail;
+
+  mkRelatedOption = desc: lib.mkEnableOption desc // { default = cfg.enable; };
+in
 {
   imports = [
     ./accounts.nix
+    ./msmtp.nix
   ];
 
+  options.my.home.mail = with lib; {
+    enable = my.mkDisableOption "email configuration";
+
+    msmtp = {
+      enable = mkRelatedOption "msmtp configuration";
+    };
+  };
+
   config = {
     accounts.email = {
       maildirBasePath = "mail";