Subject: Mail delivery failed: returning message to sender
From: "Mail Delivery System" <[email-masked]>
To: <[email-masked]>
Date: Sat, 30 Mar 2024 07:40:20 +0330

This message was created automatically by mail delivery software.

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

  [email-masked]
    host w00ac44e.kasserver.com [85.13.137.4]
    SMTP error from remote mail server after RCPT
TO:<[email-masked]>:
    550 5.1.1 <[email-masked]>: Recipient address rejected:
    User unknown in virtual alias table
  [email-masked]
    host mx01.emig.gmx.net [212.227.17.5]
    SMTP error from remote mail server after RCPT TO:<[email-masked]>:
    550 Requested action not taken: mailbox unavailable
  [email-masked]
    host mx02.t-online.de [194.25.134.9]
    SMTP error from remote mail server after initial connection:
    554 IP=159.69.236.107 - Dialup/transient IP not allowed. Use a
mailgateway or contact [email-masked] if obsolete. (DIAL)
  [email-masked]
    host mx02.t-online.de [194.25.134.9]
    SMTP error from remote mail server after initial connection:
    554 IP=159.69.236.107 - Dialup/transient IP not allowed. Use a
mailgateway or contact [email-masked] if obsolete. (DIAL)