Error sending from my email server to outlook.com + error in support request form

Question

I get this error message when sending a message from my email server to outlook

host eur.olc.protection.outlook.com[104.47.18.97]
said: 550 5.7.1 Unfortunately, messages from [xxx.xxx.xxx.xxx] weren't sent.
Please contact your Internet service provider since part of their network
is on our block list (S3140). You can also refer your provider to
[http://mail.live.com/mail/troubleshooting.aspx#errors].
[AM6EUR05FT058.eop-eur05.prod.protection.outlook.com
2024-02-22T14:38:06.572Z 08DC33434A1AF183] (in reply to MAIL FROM command)

I tried to use

https://olcsupport.office.com/

to send a support request but the form does not work. (the email field is prefilled with my account name, is non modifiable, and says it's not an email address when I submit)

What can I do ?

thanks

Answer 1

Hi @jonathan foucher

Welcome to our forum!

For better research, I would like to know that your account is also @outlook. com?

Based on error code 550 5.7.1, typically, this error indicates that a security setting in your organization or a security setting in the recipient's organization is preventing your message from reaching the recipient.

Please try to fix it in the way of this document: Fix NDR error 550 5.7.1 in Exchange Online - Exchange | Microsoft Learn.

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