Subject: Mail Delivery Failure
From: Mail Delivery System <[email-masked]>
To: <[email-masked]>
Date: Fri, 29 Jan 2021 20:49:32 +0000

This is the mail delivery agent at Symantec Email Security.cloud.

I was unable to deliver your message to the following addresses:

[email-masked]

Reason: 550 #5.1.0 Address rejected.

The message subject was: You are very pleasant.
The message date was: Fri, 29 Jan 2021 23:49:23 +0300
The message identifier was: BB/CA-14660-CD474106
The message reference was: server-14.tower-267.messagelabs.com!1611953369!1427073!1

Please do not reply to this email as it is sent from an unattended mailbox.
Contact your email administrator if you need more information, or
instructions for resolving this issue.