mail_dkim_privatekeyfile

Name: DKIM Private key file Type: String Default: (empty)

The absolute path to the private key file used to sign outgoing mail. The file must be readable by the PHP process and must not be publicly accessible.

If both this setting and mail_dkim_privatekeystring are set, the key string takes precedence.

The value is passed to PHPMailer by core/src/Revolution/Mail/modMail.php.