Return-Path: <> Date: Tue, 15 Sep 2026 09:12:33 +0200 From: Mail Delivery System To: bounce@pressekonto.com Subject: Undelivered Mail Returned to Sender Message-ID: <20260915071233.ABC123@mx.kasserver.com> Content-Type: multipart/report; report-type=delivery-status; boundary="ABC123.1758112353/mx.kasserver.com" This is a MIME-encapsulated message. --ABC123.1758112353/mx.kasserver.com Content-Description: Notification Content-Type: text/plain; charset=us-ascii This is the mail system at host mx.kasserver.com. I'm sorry to have to inform you that your message could not be delivered to one or more recipients. : host mail.alte-firma.example[192.0.2.10] said: 550 5.1.1 : Recipient address rejected: User unknown in virtual mailbox table (in reply to RCPT TO command) --ABC123.1758112353/mx.kasserver.com Content-Description: Delivery report Content-Type: message/delivery-status Reporting-MTA: dns; mx.kasserver.com X-Postfix-Queue-ID: 4XyZ12 X-Postfix-Sender: rfc822; bounce@pressekonto.com Arrival-Date: Tue, 15 Sep 2026 09:12:30 +0200 Final-Recipient: rfc822; Presse@Alte-Firma.example Original-Recipient: rfc822;presse@alte-firma.example Action: failed Status: 5.1.1 Remote-MTA: dns; mail.alte-firma.example Diagnostic-Code: smtp; 550 5.1.1 : Recipient address rejected: User unknown in virtual mailbox table --ABC123.1758112353/mx.kasserver.com Content-Description: Undelivered Message Headers Content-Type: text/rfc822-headers Return-Path: From: pressekonto To: presse@alte-firma.example Subject: Ihre Pressemitteilung wurde veroeffentlicht X-Pk-Ref: pm:4711:company:815 Message-ID: --ABC123.1758112353/mx.kasserver.com--