diff --git a/api.php b/api.php
index c0c1037..806f46a 100644
--- a/api.php
+++ b/api.php
@@ -2955,6 +2955,10 @@ switch ($action) {
         } else {
             $mb['smtp_password'] = $existingMb ? ($existingMb['smtp_password'] ?? '') : '';
         }
+        // Jos SMTP-salasana on tyhjä mutta käyttäjä on sama kuin IMAP → kopioi IMAP-salasana
+        if (empty($mb['smtp_password']) && $mb['smtp_user'] === $mb['imap_user']) {
+            $mb['smtp_password'] = $mb['imap_password'];
+        }
 
         if (empty($mb['nimi'])) {
             http_response_code(400);