We are hosting our website (http://www.redappleapartments.com) with a hosting company in Sweden. And we are using godaddy as our email provider. So, our smtp servers are smtp.europe.secureserver.net mailstore1.europe.secureserver.net Our website sends plenty of emails to our customers and we are sending via godaddy (using SMTP authentication). Some of the emails are never delivered to the recipients. And sometimes we see such warning: The hostname in the SMTP greeting does not match the reverse DNS (PTR) Can somebody out there suggest how we can solve this problem?