Package dkim is a pure Go DKIM verification library.
The main use-case for the dkim package is verifying DKIM "ownership proofs" of
e-mail addresses. The owner of an e-mail address can sent DKIM-signed
e-mails, and anyone in the world can verify that those e-mail were sent
by the owner by checking the DKIM signature. The dkim package exposes an API
to verify DKIM signatures, and to inspect the signed headers of the e-mail.
As an added feature, the dkim package supports extracting and verifying just
the signed headers of an e-mail. This makes ownership proofs much shorter.