From 64b3e04d3f8dbf65e25e94da960ab76c91a40336 Mon Sep 17 00:00:00 2001
From: Louis Lam <louislam@users.noreply.github.com>
Date: Thu, 6 Jan 2022 14:34:45 +0800
Subject: [PATCH] Fix #1129

---
 server/notification-providers/smtp.js | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/server/notification-providers/smtp.js b/server/notification-providers/smtp.js
index 1be68aeab..d85ee88c9 100644
--- a/server/notification-providers/smtp.js
+++ b/server/notification-providers/smtp.js
@@ -14,16 +14,20 @@ class SMTP extends NotificationProvider {
             secure: notification.smtpSecure,
             tls: {
                 rejectUnauthorized: notification.smtpIgnoreTLSError || false,
-            },
-            dkim: {
+            }
+        };
+
+        // Fix #1129
+        if (notification.smtpDkimDomain) {
+            config.dkim = {
                 domainName: notification.smtpDkimDomain,
                 keySelector: notification.smtpDkimKeySelector,
                 privateKey: notification.smtpDkimPrivateKey,
                 hashAlgo: notification.smtpDkimHashAlgo,
                 headerFieldNames: notification.smtpDkimheaderFieldNames,
                 skipFields: notification.smtpDkimskipFields,
-            }
-        };
+            };
+        }
 
         // Should fix the issue in https://github.com/louislam/uptime-kuma/issues/26#issuecomment-896373904
         if (notification.smtpUsername || notification.smtpPassword) {