Subject: [Mail Delivery System] Undelivered Mail Returned to Sender

From: Marius Bakke <[email-masked]>
Date: Tue, 08 Aug 2017 00:18:28 +0200

Arun, the previous email bounced at my mail server:

Diagnostic-Code: X-Postfix; Host or domain name not found. Name service error
    for name=hrrol.systemreboot.net type=A: Host not found

...in case you wonder where the replies are.