How to Add DKIM Keys to Your Sendmarc-Managed Domain

DKIM (DomainKeys Identified Mail) is an email authentication protocol that allows a sending domain to digitally sign its emails using a private key. This enables receiving email servers to verify the message’s authenticity and integrity using a public key published in the sender’s DNS. 

Pre-requisites

In order to complete the below steps, you will need to have Administrator permissions in Sendmarc.

You will need to periodically add DKIM keys to your domain to authorize sources allowed to send on your behalf – this guide assumes that you already have access to the key required for your particular provider. This guide will assume that you’re trying to authorize Sendgrid, but the process is exactly the same regardless of provider.

After following the SendGrid instructions, you’re required to add the following key:

HostTypeValue
s1._domainkey.yourdomain.comCNAME_domainkey.uXXX.wlXXX.sendgrid.net

Steps in Sendmarc

Performing this action on Sendmarc is simple – just follow these steps: 

  1. Log in to the Sendmarc Portal. 
  2. Click on ‘Domains’ on the left-hand panel. 
  3. Find your domain in the listing and click ‘Edit’ (pencil icon) next to the domain name. 
  4. Click ‘DKIM Settings’ on the right–hand panel. 
  5. Click ‘Add a Public Key’. 
  6. Under ‘Selector,’ add the provided host value. In the above example, this is ‘s1’. Note that you’re only copying the text before the first full stop. 
  7. Under ‘Record Type,’ select either CNAME or TXT as required by the sender. In our example, we select CNAME. 
  8. Copy the entire value into the ‘Value’ textbox. Note here that we’re using the full string – in our example, this means ‘_domainkey.uXXX.wlXXX.sendgrid.net’. 
  9. Optional: Update the ‘Description’ section with the details of this change. 
  10. Click ‘Save’ underneath the form you’ve just completed. 
  11. Click ‘Save’ at the bottom of the ‘DKIM Settings’ page. 

Service Provider Documentation

Looking for how to generate DKIM keys for a specific provider? Check our knowledgebase for more details.

Looking for how to configure SPF in Sendmarc?

Find out how to configure your Sendmarc-managed SPF Settings here.