Every domain registered at 1&1 IONOS automatically owns the CNAME record _domainconnect (_domainconnect.1and1.com). This DNS record simplifies the connection between a domain at 1&1 IONOS and an external website at other website services or e-shop providers via the Domain Connect protocol.
The Domain Connect protocol is an open standard that automatically connects one domain and an external website to other website services. For you as a user, this has the advantage that you can easily connect your domain to other providers of websites and e-shops without having to worry about technical details of the DNS settings.
The record _domainconnect has no effect on your DNS settings. You can enter other CNAME records at any time. We recommend that you do not delete this CNAME record, otherwise your domain will no longer support the Domain Connect protocol at 1&1 IONOS.