Reporting-MTA: dns; a48-100.smtp-out.amazonses.com

Action: failed
Final-Recipient: rfc822; xxxxxxxxxx@xx.xxxxx.xx.xx
Diagnostic-Code: smtp; 550 Invalid Recipient - https://community.mimecast.com/docs/DOC-1369#550 [DCm94spVNyqPkWw-kVQQTw.usb23]
Status: 5.3.0