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Email sending subdomains

Delegate a subdomain to Cordial

Cordial recommends that DNS be delegated from our clients to Cordial so that our systems can ensure the most optimal availability, performance and minimal ongoing maintenance on the client side.

In order to optimize your brand's deliverability reputation, Cordial recommends using branded domains inside email headers. To accomplish this, we require a unique subdomain be allocated specifically for email deploying from the Cordial platform.

A subdomain may be used for:

  • Message from domain
  • Return-Path domain

Choose a subdomain

When choosing a subdomain, it is important to verify that no other services are using (or will continue to use) the domain once it is used within Cordial.  

For example, if your main/parent domain is and you are currently using with another provider, you might consider using or another similar subdomain.   

It is recommended that different subdomains be used for each email content send type: Promotional and Transactional sends.  For example, promotional sends might be set up with and transaction sends set up with or possibly  The domains only need to differ by one character for this purpose.  

Be sure to validate that the domain(s) you choose are not being used by accessing your DNS provider and checking records that are currently published.  If you do not have access to your DNS provider, you can check if a record exists by using a publicly available DNS checker.  Cordial recommends

Once a domain is chosen, it's time to set up the DNS records to point to Cordial.

Assuming no existing records conflict, create four NS (or nameserver) records for the subdomain (e.g., and point each record to the following name servers:


Maintain your own subdomain

In the case where delegation is not possible (by policy or DNS vendor capability), Cordial can provide a set of DNS records (e.g., SPF, DKIM) that will be used in lieu of delegation.  Contact your account manager for details.  

Cordial is aware of the following DNS providers who currently do not support delegation:

  • DirectNIC (

Cordial has validated functionality with:

  • GoDaddy
  • Amazon Web Services
  • Dyn
  • Most on-premise solutions (bind, etc.)

Please let your account manager know that this process is complete and then Cordial will validate and complete the setup process and verify records.



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