Make sure to enter a return address in the from settings, especially if the from address is a dynamically generated address form the form.
Either the from Address or the Return Address must be a valid email address on the SMTP servers domain.
Origination and X-Mailer are optional headers.
Organization is Organization to which the sender of this article belongs. Mostly used for company emails
X-Mailer is the program used to create the message. In this case it should be PHP Script, but again it is optional.