Sentinel Messaging utilizes a block list service named: Proofpoint Dynamic Reputation, or PDR. Sentinel Messaging utilizes PDR for inbound email. IPs listed on PDR will block a message prior to delivery to the account.
IPs listed on Sentinel Messaging’s PDR may receive a bounce back with response blocked by PDR.
Any IP listed on the PDR service can be removed by following the link here. The conditions for PDR listings are also listed on this page.
The main reasons why we may blocking an IP:
- emails are hitting Sentinel Messaging spam traps
- emails are being reported as spam
- IPs in bulk ranges are sending spam
Sentinel Messaging customers IPs listed
Any Sentinel Messaging customer that has their IPs listed on PDR, please open a PDR request ticket first via PDR Removal Request. Upon creating the request, at the end you are given a reference ID. Please open a standard support ticket to Sentinel Messaging support and include the reference ID indicating you are following up with a PDR removal request.
Data from PDR listings
For data compliance, we may not be able to provide any details regarding why IPs got listed on PDR.
Sentinel Messaging also use the following block list services therefore customers are advised to check with these services for blocked IP’s:
If the sending IP address is blacklisted the sender will receieve a bounce-back from our server. This should make the sender aware that the mail has not been delivered and they should begin the process of getting removed from the list.