Simplistic tool to check our ARC implementation. The arc chain in the given email is validated, and a new arc signature is created. For this you must enter the private key, key domain and key selector. A private key can be generated, but for a validating signature the corresponding public key must be added to the DNS. The arc-authentication-results header is copied from an existing authentication-results signature in the email, using the provided authserv-id. If no such authentication-results exists, an empty arc-authentication-results is set.