Step 1: Check if your subdomain already has a DMARC Record:
- Go to https://dmarcian.com/dmarc-inspector
- Input your subdomain address (e.g., mail.yourdomain.com) and initiate the inspection. If a valid DMARC record exists, there’s no need to proceed further
- If there’s no record, move to the next step.
Step 2: Access Your DNS Hosting Provider:
- Log in to your DNS hosting provider’s dashboard. This is where your domain’s DNS records are managed.
- Locate the domain to which you want to add the DMARC.
Step 3: Create a new TXT Record
- Look for the option to add a new DNS record. When found, select “TXT” as the type of record you want to create.
Step 4: Configure the DMARC Record for Your Subdomain:
- In the Host/Name field, enter _dmarc.[mail] as the host.
- For the TXT record’s value, start with a basic DMARC policy: v=DMARC1; p=none;
- Save Your New TXT Record:
Here’s an example of what your DMARC for a subdomain of mail.yourdomain.co.uk should look like:
Step 5: Verify the DMARC Record for Your Subdomain:
- Re-check the DMARC record for your subdomain using the same DMARC checker tool to ensure it’s recognised correctly.
- Additionally, you can send a test email from your subdomain to a service like Gmail and inspect the email’s header for DMARC information. In Gmail, find this by clicking the three dots next to the reply button and selecting “Show original.”
DNS changes may take some time to propagate, so it could be a few minutes to several hours before the new record is active.