[BlueOnyx:22992] Mail Delivery Subsystem error — received from localhost

[Meaulnes Legler @ MailList]

hello

I get quite often burst of Mail Delivery error messages, hundreds in a minute or two like the one below, addressed to «myhostname».localdomain. Then it stops by itself and restarts a couple of days later.

Weird is the line: Received-From-MTA: DNS; localhost

Any idea from where this comes from? and how to prevent this?

Thank you and best regards

_⌢_  Meaulnes Legler
'¿') Zurich, Switzerland.
`-´  +41¦0 44 260-1660 fax:-1661

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The original message was received at Mon, 1 Jul 2019 05:00:21 +0200
from localhost
with id x6130LRY022291

    ----- The following addresses had permanent fatal errors -----
<mailman-bounces at bleue.localdomain>
     (reason: 550 Host unknown)

    ----- Transcript of session follows -----
550 5.1.2 <mailman-bounces at bleue.localdomain>... Host unknown (Name server: bleue.localdomain: host not found)


Reporting-MTA: dns; bleue.waveweb.ch
Received-From-MTA: DNS; localhost
Arrival-Date: Mon, 1 Jul 2019 05:00:21 +0200

Final-Recipient: RFC822; mailman-bounces at bleue.localdomain
Action: failed
Status: 5.1.2
Remote-MTA: DNS; bleue.localdomain
Diagnostic-Code: SMTP; 550 Host unknown
Last-Attempt-Date: Mon, 1 Jul 2019 05:00:21 +0200


Return-Path: <MAILER-DAEMON>
Received: from localhost (localhost)
	by bleue.waveweb.ch (8.14.7/8.14.7) id x6130LRY022291;
	Mon, 1 Jul 2019 05:00:21 +0200
Date: Mon, 1 Jul 2019 05:00:21 +0200
From: Mail Delivery Subsystem <MAILER-DAEMON>
Message-Id: <201907010300.x6130LRY022291 at bleue.waveweb.ch>
To: <mailman-bounces at bleue.localdomain>
MIME-Version: 1.0
Content-Type: multipart/report; report-type=delivery-status;
	boundary="x6130LRY022291.1561950021/bleue.waveweb.ch"
Subject: Returned mail: see transcript for details
Auto-Submitted: auto-generated (failure)

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