What are Known Forwarders?

Known forwarders are third-party systems that are known to do automated forwarding of emails. Known Forwarders are systems that the Valimail platform detects as being the last email service that delivered the email and it is not the same service where the email originated from. 

Where do I see Known Forwarders in the Authentication Dashboard?

The first is as a drill down of a specific service. This shows emails that originated with the service but were then forwarded by the Known Forwarder. In some cases, there will be a Known Forwarder called ‘Unknown’ This shows the authentication status for emails that were known to have originated with the service but were forwarded through a third party for which the Valimail platform can't identify from the data found in the DMARC aggregate reports.


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The second place that Known Forwarders appears is as a drill down beneath the Unidentified Senders section. This shows emails that are known to have been forwarded but which the Valimail platform is not able to determine the actual originating service.

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Why do we classify known forwarders as unidentified senders?

The Valimail platform classifies some known forwarders as unidentified senders due to three reasons:

  • In many cases, when an email is forwarded, the forwarder will change the return path to be themselves. If the email is not DKIM signed, The Valimail platform can not identify the originating service using the return path.
  • Some email receivers do not include the DKIM selector for DKIM-signed emails in the DMARC reports. When the email is forwarded in these cases, The Valimail platform can not identify the service based on the DKIM selector.
  • There are some cases where emails are being automatically forwarded through more than one Known Forwarder, due to these multiple bounces, The Valimail platform can not identify the originating service.

As always, if you have any questions, please don't hesitate to submit a ticket.