All domains registered with IONOS are automatically assigned a _domainconnect _domainconnect.1and1.com) CNAME record. This DNS record simplifies the connection between a domain at IONOS and an external website hosted by third party website services or e-shop providers using the Domain Connect protocol.
The Domain Connect protocol is an open standard which automatically connects a domain to an external website. For you as a user, this has the advantage that you can easily connect your domain to third party websites and e-shops without having to worry about the DNS settings.
The _domainconnect record has no effect on your other DNS settings. You can create additional CNAME records as needed. We recommend that you do not delete this CNAME record, otherwise your IONOS domain will no longer support the Domain Connect protocol.