Fix MX record format in send.adaptable.json

domains/send.adaptable.json

@@ -5,7 +5,7 @@
     },
     "records": {
         "MX": [
-            "10 feedback-smtp.ap-northeast-1.amazonses.com"
+            "feedback-smtp.ap-northeast-1.amazonses.com"
         ],
         "TXT": "v=spf1 include:amazonses.com ~all"
     }