Quand on héberge son serveur de courriel on se retrouve parfois refusé par les serveurs Microsoft (hotmail, outlook). Ça prend la forme d'un message comme ceci :
host hotmail-com.olc.protection.outlook.com[52.101.68.20] 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 (S3150). You can also refer your provider to
http://mail.live.com/mail/troubleshooting.aspx#errors. [Name=Protocol
Filter Agent][AGT=PFA][MxId=11BB8988E9FA7587]
DU6PEPF0000A7E4.eurprd02.prod.outlook.com 2025-07-17T16:11:05.544Z
08DDC4C476023DD9] (in reply to MAIL FROM command)
Apparemment, Microsoft bloque des (…)