NDR - Status code: 550 5.7.368

Mohammed Faizal 5 Reputation points
2024-07-27T00:34:29.5133333+00:00

One of our clients has sent an email and have received this error message, please advise how we can isolate it.

Below are the complete error details

‎"550 Reason: [{LED=550-Please turn on SMTP Authentication in your mail client, or login to the 550-IMAP/POP3 server before sending your message. 550-mail-bn7nam10on2137.outbound.protection.outlook.com 550-(NAM10-BN7-obe.outbound.protection.outlook.com) [40.107.92.137]:29793 is 550 not permitted to relay through this server without. OutboundProxyTargetIP: xx.xx.xx.xx. OutboundProxyTargetHostName: mail.domain.com‎"

Microsoft 365
Microsoft 365
Formerly Office 365, is a line of subscription services offered by Microsoft which adds to and includes the Microsoft Office product line.
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  1. Mohd Ishaque 0 Reputation points
    2024-07-29T16:58:12.82+00:00

    Ultimately, the issue resides with the recipient’s email server and can’t be fixed by yourself.

    Before contacting the intended recipient via a different method to let them know of the issue (eg, by using a different email address or calling them by phone), you may first wish to check the message at the very top of the bounce-back email to confirm that you are sending the email to the correct address;

    “Your message to [recipient email address] couldn’t be delivered.”

    If this address is incorrect or not the address you were expecting, you may simply need to re-send the email to the correct email address.

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