Description
DKIM1 is supported by the Mailer Component. There is also documentation2.
Syntax
use Symfony\Component\Mime\Crypto\DkimSigner;
use Symfony\Component\Mime\Email;
$email = (new Email())
->from('[email protected]')
// ...
->html('...');
$signer = new DkimSigner('file:///path/to/private-key.key', 'example.com', 'sf');
$signedEmail = $signer->sign($email);