Subject: Undelivered Mail Returned to Sender
From: MAILER-DAEMON@LOCALHOST (Mail Delivery System)
To: [email-masked]
Date: Sat, 29 Oct 2022 10:09:53 +0900 (JST)

This is the Email Security Gateway at host mail4.Marine-onair.net.

I'm sorry to inform you that the message below could not be delivered.
When delivery was attempted, the following error was returned.

<[email-masked]>: connect to
    192.168.90.105[192.168.90.105]:25: No route to host