Proofpoint Essentials Adds Cloudmark Sender Intelligence

Created by Yves Lacombe, Modified on Tue, 25 Feb 2020 at 09:16 AM by Jason Carreiro

Cloudmark Sender Intelligence Reputation Service

After it's acquisition of cloudmark, Proofpoint has integrated cloudmark's threat intelligence to its spam filtering service on Proofpoint Essentials at the connection level.   This adds an extra component to Proofpoint's own reputation system.

The official name of the feature is called Cloudmark Sender Intelligence. Proofpoint Essentials utilizes CSI for inbound email. IPs listed on CSI will block a message prior to delivery to the account. IPs listed on Proofpoint's CSI may receive a bounce back with response blocked by CSI. However, this will be apparent in the sender logs where it will give the error of IP blocked using Cloudmark Sender Intelligence.

For example,

550 5.7.1 Service unavailable; client [] blocked using Cloudmark Sender Intelligence (Visit if you feel this is in error.)

If you're trying to receive emails for a domain that is blocked by Cloudmark, the sender needs to initiate a delisting request:

  • Many providers will use a shared IP address for their services. If other users are sending mail out from the same IP address as your sender, their sending patterns could be the reason for the poor reputation.
  • The sender could have malware on a PC on the same network as the sending server sending spam or a compromised account
  • If you’re sender is sending a newsletters then, there might be issues with the sender's mailing practices that are causing recipients to be reported as spam. 
  • If your sender is a service provider -- it is possible that they have taken on a spammer as customer

ModusCloud / Proofpoint Essentials Customers 

If your IP is listed on CSI

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

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


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 to re-list the IP if we see fit.
  1. Go to the CSI Remediation Portal page.
  2. Complete the form and Submit

ModusCloud & 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 CSI Listings

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

If the sending IP address is blacklisted, 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.

As always, if you have any questions, feel free to contact our support team at or 514 845-8474.