Using REST API to create the package along with the documents and return a response package id. After that, we initiate a REST API signerAuthenticationToken passing packageId and email address of the signer which then redirect to an iframe to begin the signing ceremony. This is all done seamlessly without signer identity verification (email, question/answer or SMS). Is this possible? I am able to do it. Is it because I am in sandbox mode? Next question, is it necessary for signer to receive email notifications i.e. request to sign and signing ceremony complete?