DNS Setup for Register.com
Log in to Register.com. Hover over Domains, then click the Manage.
Choose Manage next to the domain name that you want to update.
To create a CNAME record, Go to the Advanced Technical Settings and click the Edit Domain Aliases Records.
Enter the Hostname we recommend into the box to left of your domain.
Note: You will only need to add the first part of the recommended hostname without your full domain name to your DNS records as your provider may automatically add it.
Enter the value that we advise for your CNAME record into the box right of points to.
Click on the Continue button. On the next page, click on the Continue button again to save the changes.
You can find the "Hostname" and "Value" under the Settings > Sender Domains section of your SMTP2GO Dashboard.
Repeat step 2 for each required CNAME record.