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Proofpoint, Inc.

Proofpoint Dynamic Reputation (PDR) IP blocklisting and IP address removal

Situation Email are bounced due to Proofpoint Dynamic Reputation IP blocklisting, and you receive a SMTP error 550 email blocked.

Raise a ticket with Proofpoint PDR service. See below for additonal information on:

  • If your IP is listed on PDR
  • Data from PDR listings
  • Remediation steps


Proofpoint Dynamic Reputation

Proofpoint has a block list service named: Proofpoint Dynamic Reputation (PDR) or Proofpoint Reputation System (PRS). Proofpoint Essentials utilizes PDR for inbound email. IPs listed on PDR will block a message prior to delivery to the account.

IPs listed on Proofpoint's PDR may receive a bounce back with response blocked by PDR. These messages do not show up anywhere in the Essentials portal logs.  However, this will be apparent to the original sender in their systems outbound sending logs where it will give the error of IP blocked by

For example, Email error 550 email blocked is primarily caused when a mail server IP is listed in a spam blocklist.

Any IP listed on the PDR service can be removed by going to the IP removal page and follow the process down below. The conditions for PDR listings are also listed on this page.

Why do we block IPs?

Primary reasons include:

  • Emails hitting Proofpoint spam traps.
  • Emails being reported as spam.
  • IPs in bulk ranges are sending spam.

Proofpoint Essentials customers 

If an IP is listed, you can find out by going to the PDR check page. If listed, the page will look like this:

pdr lookup.JPG

If your IP is listed on PDR

Any Proofpoint Essential customer that has their own IPs listed on PDR, please:

  • Open a PDR request ticket first via PDR Removal Request. Upon creating the request, at the end you should be provide a reference ID.
  • Open a standard support ticket to Proofpoint Essentials support and include the reference ID indicating you are following up with a PDR removal request. 
    • If the reference ID is not available, make sure to provide the IP.

Requesting IP removal

Please note that a Proofpoint Enterprise customer can log into the PCSC portal to log a ticket directly regarding this. All others must follow the process below.

IP Owner/User

  • The owner or company using the IP should be following the removal process. Please do not file a ticket on behalf of another company, as you may not be able to follow the remediation steps if applicable. 
  • If you do open a ticket on behalf of another company, please note that we do reserve the right ot re-list the IP if we see fit.
  1. Go to the PDR Removal Request page.
  2. Enter in the IP and check the reCAPTCHA box (screen shot above).
    • If the next page indicates the IP address is not blocked, but the errors continue, please open a ticket with the appropriate support with the IP so we can investigate this further.
  3. The form in question should be filled out by the IP owner. 
    • As a customer, you can fill out the form, however, certain remediation steps required may not be available for you to perform, hence why the IP owner should be contacting us.
  4. Please note that the Additional Details section is required. 
    • The details should be very specific in nature of what the email is and/or the issue that caused this and if you have remediated the issue.
  5. Click Submit and a ticket will be generated.

Proofpoint Essentials Customers

As indicated above, the IP owner should be the one to fill out this form so remediation steps can be followed up with. Once a ticket has been filed, please file a ticket with support to follow-up.

Data from PDR listings

For data compliance, we may not be able to provide any details regarding why IPs got listed on PDR.

If the sending IP address is blocklisted, the sender will receive 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.

Remediation steps

The remediation steps to help are to help the IP owners/users with mail delivery. This can help them clear up other delivery issues they may be having with other providers as well.

PTR change

One of the remediation steps is due to dynamic PTR records. If the PTR record appears to be a shared or widely abused service, changing to a more personalized PTR will quickly help identify that this is a legitimate service.