Mail::MIMEDefang::DKIM - DKIM interface for MIMEDefang

Mail::MIMEDefang::DKIM is a module with a set of DKIM related methods
called from mimedefang-filter to operate with DKIM.

md_dkim_sign
    Returns a mail header and the DKIM signature for the message. The
    method accepts the following parameters:

    $keyfile
        The path to the private DKIM key

    $algorithm
        The algorithm to be used to sign the message, by default is
        'rsa-sha1'

    $method
        The method used to sign the message, by default is 'relaxed'

    $domain
        The domain to be used when signing the message, by default it's
        autodetected

    $selector
        The selector to be used when signing the message, by default
        it's 'default'

    $headers
        The headers to sign, by default the headers are: From Sender
        Reply-To Subject Date Message-ID To Cc MIME-Version Content-Type
        Content-Transfer-Encoding Content-ID Content-Description
        Resent-Date Resent-From Resent-Sender Resent-To Resent-cc
        Resent-Message-ID In-Reply-To References List-Id List-Help
        List-Unsubscribe List-Subscribe List-Post List-Owner
        List-Archive

md_dkim_verify
    Verifies the DKIM signature of an email. Return value can be "pass",
    "fail", "invalid", "temperror", "none". In case of multiple
    signatures, the "best" result will be returned. Best is defined as
    "pass", followed by "fail", "invalid", and "none". The second return
    value is the domain that has applied the signature. The third return
    value is the size of the DKIM public key. The forth return value is
    the value of the "b" tag of the DKIM signature.