FTR outlook.com has blacklisted my mailserver from Jan Wildeboer on 2023-05-22 (public-swicg@w3.org from May 2023)

From: Jan Wildeboer <jan@wildeboer.net>
Date: Mon, 22 May 2023 18:45:51 +0200
To: public-swicg@w3.org
Message-Id: <5959DA7E-D1E6-4436-B522-0DE3135F1660@wildeboer.net>

It only seems to affect saschanaz@outlook.com <mailto:saschanaz@outlook.com> and the error message doesn’t really give me a hint on how to resolve this. The IP address of my mail server hasn’t changed in years and works everywhere else, so I apologise to saschanaz and would be grateful to learn about any hints on how to get this block resolved.

Jan

Remote-MTA: dns; outlook-com.olc.protection.outlook.com
Diagnostic-Code: smtp; 550 5.7.1 Unfortunately, messages from [51.38.32.100]
   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.
   [AM6EUR05FT021.eop-eur05.prod.protection.outlook.com
   2023-05-22T16:10:53.947Z 08DB59F810DB0376]

Received on Monday, 22 May 2023 16:46:09 UTC