Php – “Signed” email in PHP


How would one "sign" an outgoing email using PHP?

The proper header I am looking at is:


Best Solution

If I understand you correctly, you want to generate a signed e-mail using PHP.

The standard way to send signed e-mails is S/MIME (another less common way is PGP). S/MIME is basically a MIME message containing the base64-encoding of a CMS message (CMS is also sometimes called PKCS#7).

One way to do this from PHP is with the PHP-bindings to OpenSSL's openssl_pkcs7_sign.

I have no idea what the signed-by header should be used for.