For a complete guide on adding a CNAME record to 1&1 IONOS, see their documentation on Configuring a CNAME Record for a Subdomain.
Or, try out Unbounce's automatic CNAME setup for 1&1 hosted domains. Check out the article to learn more: Adding Your Domain Automatically (GoDaddy, Media Temple or 1&1).
If you run into any issues and would like to manually set up your domain with 1&1 IONOS, please contact 1&1 IONOS' Support teams directly.
