5 <p><a href=
"https://aws-portal.amazon.com/gp/aws/html-forms-controller/contactus/ec2-email-limit-rdns-request">Here
</a> is the form to request a custom PTR record for an Amazon EC2 Elastic IP. It's included under
<u>Request to Remove Email Sending Limitations
</u>, which is not helpful.
</p>
6 <p>This is good when setting up a mail server in Amazon's cloud. Without this request, the reverse DNS lookup will the default PTR record - something like
<a href=
"http://ec2-50-16-219-8.compute-1.amazonaws.com">ec2-
50-
16-
219-
8.compute-
1.amazonaws.com
</a>. When the reverse DNS record doesn't match the origin domain, mail providers like GMail are likely to mark your mail as spam.
</p>