Podee has chosen not to receive private messages or may not be allowed to receive private messages. Therefore you may not send your message to him/her.
If you are trying to send this message to multiple recipients, remove Podee from the recipient list and send the message again.
If you go to his profile, click on "contact info," and click on "send message via email" you can email him / her. With only 1 post the PM thing may be disabled.