fix: join confirmation mail configuration

lib/mv_web/emails/join_confirmation_email.ex

@@ -15,11 +15,11 @@ defmodule MvWeb.Emails.JoinConfirmationEmail do
   @doc """
   Sends the join confirmation email to the given address with the confirmation link.
 
+  Uses the same SMTP configuration as the test mail (Settings or boot ENV) via
+  `Mailer.deliver/2` with `Mailer.smtp_config/0` for consistency.
+
   Called from the domain after a JoinRequest is created (submit flow).
   Returns `{:ok, email}` on success, `{:error, reason}` on delivery failure.
-  Callers should log errors and may still return success for the overall operation
-  (e.g. join request created) so the user is not shown a generic error when only
-  the email failed.
   """
   def send(email_address, token) when is_binary(email_address) and is_binary(token) do
     confirm_url = url(~p"/confirm_join/#{token}")
@@ -32,12 +32,14 @@ defmodule MvWeb.Emails.JoinConfirmationEmail do
       locale: Gettext.get_locale(MvWeb.Gettext)
     }
 
-    new()
-    |> from(Mailer.mail_from())
-    |> to(email_address)
-    |> subject(subject)
-    |> put_view(MvWeb.EmailsView)
-    |> render_body("join_confirmation.html", assigns)
-    |> Mailer.deliver()
+    email =
+      new()
+      |> from(Mailer.mail_from())
+      |> to(email_address)
+      |> subject(subject)
+      |> put_view(MvWeb.EmailsView)
+      |> render_body("join_confirmation.html", assigns)
+
+    Mailer.deliver(email, Mailer.smtp_config())
   end
 end