Subject: Undelivered Mail Returned to Sender
From: [email-masked] (Mail Delivery System)
To: [email-masked]
Date: Sun, 30 Oct 2022 03:47:25 +0000 (GMT)

This is the mail system at host mta652.mel.oss-core.net.

I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to <[email-masked]>

If you do so, please include this problem report. You can
delete your own text from the attached returned message.

                   The mail system

<[email-masked]>: host mailstore.service.int.oss-core.com[172.28.72.112]
    said: 550 5.1.1 <[email-masked]> User doesn't exist:
    [email-masked] (in reply to RCPT TO command)