Seems to be some conflation in this thread. Are DKIM and authentication (PGP) really comparable in practice? Here's my take: DKIM is an attempt by _third part

Seems to be some conflation in this thread. Are DKIM and authentication (PGP) really comparable in practice? Here's my take: DKIM is an attempt by _third parties_ (i.e. "email providers", not the author or the recipient of the message) to control who can send email (but guess what? anyone can send email, go figure). On the other hand, authentication (PGP) is an attempt to allow senders to sign messages and receivers to verify signatures (no third parties needed). Bob printed his PGP public key on a card and gave it to Alice when they had lunch. He then signed an email message the following week using PGP and sent it to Alice. But Bob's "email provider" decided to block Bob's message because Bob didn't pay money to someone for the use of a "domain name" and Bob's "email provider" thought his email was "spam" because he hadn't been "authorized" (by paying money for use of a domain name) to send email.