I have just had a failure sending to any hotmail.com, hotmail.co.uk and live.com addresses
Final-recipient: rfc822; @XX@hotmail.com
Diagnostic-Code: smtp; 550 5.7.1 Unfortunately, messages from [212.159.14.17] 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. [Name=Protocol Filter Agent][AGT=PFA][MxId=11BCEBBEF940A923]
[AMS1EPF0000008D.eurprd05.prod.outlook.com 2026-02-27T19:59:41.988Z 08DE75DF7D8AD389]
Last-attempt-Date: Fri, 27 Feb 2026 19:59:42 +0000
