leopope on "[Plugin: Contact Form 7] Error sending message via Contact form on Daisho"

I've got the red error message using Contact Form 7 on this theme: http://www.leopope.com/contact/

I use bluehost and I've tried this, as recommended on your FAQ: http://angstrey.com/index.php/2009/04/22/how-to-send-e-mail-with-wordpress-from-godaddy-windows-hosting/. Does that work only for GoDaddy users?

Thanks in advance. Best regards,

http://wordpress.org/extend/plugins/contact-form-7/