Returned mail: see transcript for details

From: MAILER-DAEMON@ip-172-31-11-86.ec2.internal
Domain: IP info ip-172-31-11-86.ec2.internal
MX-server: IP info ip-172-31-11-86.ec2.internal
Size: 1040 Bytes
Create: 2025-01-24
Update: 2025-01-25
Score: 0
Safe: Yes

The original message was received at Fri, 24 Jan 2025 18:58:00 -0500 from localhost [127.0.0.1] ----- The following addresses had permanent fatal errors ----- (reason: 550 5.7.606 Access denied, banned sending IP [52.4.236.121]. To request removal from this list pleas...26655 AS(1427) [BL6PEPF00022572.namprd02.prod.outlook.com 2025-01-24T23:58:00.925Z 08DD3A5A849F08E6]) ----- Transcript of session follows ----- ... while talking to southernplcs-com.mail.protection.outlook.com.: >>> DATA ... User unknown