When sending a mail to outlook.com or hotmail.com, I receive following error message.
first.last@outlook.com: host
outlook-com.olc.protection.outlook.com[52.101.68.14] said: 550 5.7.1
Unfortunately, messages from [81.82.234.154] 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.
[DB1PEPF000509FD.eurprd03.prod.outlook.com 2024-05-28T17:03:42.262Z
08DC7D60E6646EF2] (in reply to MAIL FROM command)
Checking the reputation of my mail server on MXTOOLBOX seems all ok.
Anybody who has an idea how to fix this?