refactor: adress review

lib/mv/mailer.ex

@@ -33,6 +33,7 @@ defmodule Mv.Mailer do
 
   require Logger
 
+  # Simple format check for test-email recipient only (e.g. allows a@b.c). Not for strict RFC validation.
   @email_regex ~r/^[^\s@]+@[^\s@]+\.[^\s@]+$/
 
   @doc """
@@ -105,6 +106,11 @@ defmodule Mv.Mailer do
       password = Mv.Config.smtp_password()
       ssl_mode = Mv.Config.smtp_ssl() || "tls"
 
+      verify_mode =
+        if Application.get_env(:mv, :smtp_verify_peer, false),
+          do: :verify_peer,
+          else: :verify_none
+
       [
         adapter: Swoosh.Adapters.SMTP,
         relay: host,
@@ -114,10 +120,9 @@ defmodule Mv.Mailer do
         auth: :always,
         username: username,
         password: password,
-        # OTP 26+ enforces verify_peer; allow self-signed / internal certs.
-        # tls_options: STARTTLS upgrade (port 587); sockopts: direct SSL connect (port 465).
-        tls_options: [verify: :verify_none],
-        sockopts: [verify: :verify_none]
+        # tls_options: STARTTLS (587); sockopts: direct SSL (465). Verify from :smtp_verify_peer (ENV SMTP_VERIFY_PEER).
+        tls_options: [verify: verify_mode],
+        sockopts: [verify: verify_mode]
       ]
       |> Enum.reject(fn {_k, v} -> is_nil(v) end)
     else