smtp to symfony lite update

oit.module

@@ -620,3 +620,27 @@ function oit_block_access(Block $block, $operation, AccountInterface $account) {
     }
   }
 }
+
+/**
+ * Implements hook_mail_alter().
+ *
+ * Forces the From address on every outgoing message to the OIT service account
+ * (oitsrvcom@colorado.edu). Office 365 rejects mail whose From does not match
+ * an authorized sender (SendAsDenied), so this reproduces the From-rewriting
+ * the drupal/smtp module performed before the migration to Symfony Mailer Lite.
+ * Symfony Mailer Lite has no transport-level From override, so the header is
+ * forced here, after hook_mail() has run and before the message is sent.
+ *
+ * Reply-To defaults to oithelp@colorado.edu so replies still reach the help
+ * desk, but any Reply-To a module set explicitly is preserved.
+ */
+function oit_mail_alter(&$message) {
+  $from = 'Office of Information Technology <oitsrvcom@colorado.edu>';
+  $message['from'] = 'oitsrvcom@colorado.edu';
+  $message['headers']['From'] = $from;
+  $message['headers']['Sender'] = 'oitsrvcom@colorado.edu';
+  $message['headers']['Return-Path'] = 'oitsrvcom@colorado.edu';
+  if (empty($message['headers']['Reply-To'])) {
+    $message['headers']['Reply-To'] = 'oithelp@colorado.edu';
+  }
+}