feat: set up a system mailer so that errors will be emailed

modules/services/email.nix

@@ -0,0 +1,19 @@
+{
+  pkgs,
+  config,
+  ...
+}:
+{
+  programs.msmtp = {
+    enable = true;
+    accounts.default = {
+      auth = true;
+      tls = true;
+      port = 465;
+      host = "smtp.migadu.com";
+      from = config.liv.variables.senderEmail;
+      user = config.liv.variables.senderEmail;
+      passwordeval = "${pkgs.coreutils}/bin/cat ${config.sops.secrets.systemMailerPassword.path}";
+    };
+  };
+}