MSG is blocking emails due to blacklisted IP
Trying to send emails through MSG results in the following Non-Delivery Report (NDR) message:
SMTP Protocol Returned a Permanent Error 550 5.7.0 Blocked - see https://ipcheck.proofpoint.com/?ip=<ip.address.goes.here>
The sending IP-address has been blocked by Proofpoint Dynamic Reputation (PDR). This can be double-checked by visiting the page https://ipcheck.proofpoint.com
The section About Proofpoint® Dynamic Reputation (PDR) contains more information about the function as well as a link to an FAQ-page with common questions and answers, for example what to do to prevent this from happening.
To get the situation investigated quicker, open a support ticket with F-Secure. Include the IP that is blocked and information about how long the situation has been ongoing.
Article no: 000005857