DKIM Wizard in Share 5 This wizard will allow you to easily create a public and private key pair to be used for DomainKeys and DKIM signing within PowerMTA. The key pair will be used for both DomainKeys and DKIM signing. ***Policy records are no longer included as they are part of the deprecated DomainKeys, and not DKIM.*** Domain name of the “From:” header address, not the SMTP “MAIL FROM”. (e.g., port25.com) DomainKey Selector (e.g., key1) 1024 2048 Key size in bits.