diff --git a/core/server/services/bulk-email/mailgun.js b/core/server/services/bulk-email/mailgun.js
index cbb6c1be7d..8713d8afee 100644
--- a/core/server/services/bulk-email/mailgun.js
+++ b/core/server/services/bulk-email/mailgun.js
@@ -84,9 +84,11 @@ function send(message, recipientData, replacements) {
             messageData['v:email-id'] = message.id;
         }
 
+        const tags = ['bulk-email'];
         if (bulkEmailConfig && bulkEmailConfig.mailgun && bulkEmailConfig.mailgun.tag) {
-            messageData['o:tag'] = [bulkEmailConfig.mailgun.tag, 'bulk-email'];
+            tags.push(bulkEmailConfig.mailgun.tag);
         }
+        messageData['o:tag'] = tags;
 
         if (bulkEmailConfig && bulkEmailConfig.mailgun && bulkEmailConfig.mailgun.testmode) {
             messageData['o:testmode'] = true;