your Internet service provider since part of their network is on our block list (S3150)

Question

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:

 

  [xxxxxxxxx@hotmail.com]

    host hotmail-com.olc.protection.outlook.com [52.101.68.14]

    SMTP error from remote mail server after pipelined MAIL FROM:<[xxxxxx@xxxxxxxxxxxx.com]> SIZE=3602:

    550 5.7.1 Unfortunately, messages from [135.181.137.27] weren't sent. Please contact your Internet service provider since part of their network is on our block list (S3150). You can also refer your provider to [http://mail.live.com/mail/troubleshooting.as[truncated]]

i m sending email from our server... *********xxxxxxxxx.com

to any hotmail.com , its says Mail delivery failed: returning message to sender

Regards
Sayed Imran
+xxx xxxxxxxx

Answer 1

Hi @Sayad Imran ,

Welcome to our forum!

According to your description, i notice that the issue occurs when you try to send emails to any hotmail.com account. Does this issue occur when you send emails to other recipients?

And what's your account? An Exchange online account or something else?

Based on my research on the error "A message that you sent could not be delivered to one or more of its recipients. This is a permanent error", i found a similar thread mentioned that the issue may occur when you choose the recipient from auto-complete list instead of typing the email address. It's suggested that you could try to type the email address manually in From field and send the email again to check if the issue persists.

On the other hand, for the error "550 5.7.1", i found that this error indicates a security setting in your organization or the recipient's organization is preventing your message from reaching the recipient.

If you are using an Exchange account, it's suggested that you could refer to this official article and try to troubleshooting: Fix NDR error "550 5.7.1" in Exchange Online.

(Note: I notice that your mailbox address is included in your thread and have hid it. In order to avoid privacy, please remember to hide your personal information before you post.)

Hope the above help!---------

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