As a certified sender, why do I have to use dedicated IP addresses and dedicated DKIM domains?

To be accepted into Return Path's Certification program, a company's business model must meet certain requirements. One of these requirements includes only sending email from dedicated IP addresses and dedicated DKIM domains. 

Dedicated and shared IP and DKIM domain information

  • Dedicated IP addresses are those used by a single sender or company.
  • Shared IP addresses are dynamic IP addresses that can be used by thousands of senders.
  • Dedicated DKIM domains are those that are used by a single sender or company to sign and authenticate only their mail stream. 


You must use dedicated IP addresses and DKIM domains to send email. Read below for more details. 

  • Certified senders must be able to control and remain accountable for their email program's reputation.
    • Mailbox providers base sending reputation off of IP address traffic. This means if you and other companies are sharing an IP or domain, their sending behavior could negatively impact your reputation as well. 
    • You can only control your reputation and status within the Certification program by sending from a dedicated IP or DKIM domain. 
  • The metrics that Certification monitors will not be accurate for your email program if other companies are also sending from the same IP address or DKIM domain. 
    • For example, the complaint rate metric would be representative of all senders using the IP address rather than just one sender. 
Was this article helpful?
0 out of 0 found this helpful
Have more questions? Submit a request