your message could not be delivered

[billsou]

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<billsou@hotmail.com>: host
hotmail-com.olc.protection.outlook.com[104.47.18.225] said: 550 5.7.1
Unfortunately, messages from [128.199.34.175] 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.
[VI1EUR06FT053.eop-eur06.prod.protection.outlook.com] (in reply to MAIL
FROM command)
Reporting-MTA: dns; mail.ethmail.cc
X-Postfix-Queue-ID: E4A596E73E1
X-Postfix-Sender: rfc822; 0x131a858718ed52f79f5204cbc7daa6af03c694dd@ethmail.cc
Arrival-Date: Mon, 20 Jun 2022 02:39:37 +0000 (UTC)

Final-Recipient: rfc822; billsou@hotmail.com
Original-Recipient: rfc822;billsou@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 [128.199.34.175]
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.
[VI1EUR06FT053.eop-eur06.prod.protection.outlook.com]