This is the mail system at host mo587.mail-out.ovh.net.
I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.
For further assistance, please send mail to postmaster.
If you do so, please include this problem report. You can
delete your own text from the attached returned message.
The mail system
;;;;;;;;;;;>: host
hotmail-com.olc.protection.outlook.com[52.101.41.55] said: 550 5.7.1
Unfortunately, messages from [87.98.176.203] 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.aspx#errors. [Name=Protocol
Filter Agent][AGT=PFA][MxId=11BDA42C47663EB9]
[SJ5PEPF00000205.namprd05.prod.outlook.com 2026-07-01T15:41:42.199Z
08DED2162A507B54] (in reply to MAIL FROM command)
Reporting-MTA: dns; mo587.mail-out.ovh.net
X-Postfix-Queue-ID: 4gr44h504nz3wnl
X-Postfix-Sender: rfc822; ateliers@lessencememe.be
Arrival-Date: Wed, 1 Jul 2026 15:41:40 +0000 (UTC)
Final-Recipient: rfc822; ............@hotmail.com
Original-Recipient: rfc822;stock.christine@hotmail.com
Action: failed
Status: 5.7.1
Remote-MTA: dns; hotmail-com.olc.protection.outlook.com
Diagnostic-Code: smtp; 550 5.7.1 Unfortunately, messages from [87.98.176.203]
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.aspx#errors.
[Name=Protocol Filter Agent][AGT=PFA][MxId=11BDA42C47663EB9]
[SJ5PEPF00000205.namprd05.prod.outlook.com 2026-07-01T15:41:42.199Z
08DED2162A507B54]
Hi @ChristianG47
The problem you’re experiencing is very clear and, unfortunately, common when sending emails from an OVHcloud server. The 550 5.7.1 error that Hotmail returns to you is actually a reputation issue, not a technical one. That IP 87.98.176.203 has been placed on its block list.
Kind regards,
Sergio Turpín