Hi,

 

One of our hosted customers when ever tries to send email to Hotmail, his messages bounces with below reply. He is connecting from a dynamic IP, however we have many customers connecting the same way with no problems.

 

> This message was created automatically by mail delivery software.

>

> A message that you sent could not be delivered to all of its recipients. The

> following address(es) failed:

>

> XXXXXX@hotmail.com

>

> The reason for failure was as follows:

>

> 550 Mail rejected by Windows Live Hotmail for policy reasons. We

> generally do not accept email from dynamic IP's as they are not typically

> used to deliver unauthenticated SMTP email to an Internet mail server.

> http://www.spamhaus.org maintains lists of dynamic and residential IP

> addresses. Contact your ISP to determine which authorized SMTP relay servers

> to send your mail through (or) request a static and dedicated IP before

> attempting to send mail. For additional information about Microsoft's

> technical guidelines, please refer to:

> http://postmaster.live.com/Guidelines.aspx

 

Any hints please what causes this.

Thanks