I had the same problem so I wrote to Hostgator (my hosting providor). Here are my quesions and their replies:
Hello. Today I saw this page - http://www.intodns.com/There
are some problem with your server with Recursive Queries, SOA EXPIRE and Reverse MX A records (PTR). Can you please repair them? Thank you, Paul
Hello Paul, Thank you for contacting HostGator! Most all of the issues that you have listed for the domain "mysite.com" are going to be outside of the changes which we can make in regards to your accounts DNS. Specifically the nameservers for "mysite.com" are going to report as an issue for Recursive Queries. As these nameservers are Public Nameservers you are going to experience this error message. This would be an issue if you were using Private nameservers, however, as you are not this should not be an issue. Also, the SOA expire for your domain "mysite.com" is what we have found to work best with our servers configuration. As the SOA record will almost never change for your HostGator account this records expiration can be set at much higher values as it does not need to update nearly as often as an A record for example. Lastly, in regards to the reverse records for your account, as your domain "mysite.com" is on a Shared IP address you will experience this issue. You will not be able to change the PTR record of your accounts IP address unless you have a Dedicated IP address. This will not cause any issues with your accounts email sending nor your accounts A record unless you have a Dedicated IP address. Please let us know if you have any questions about anything I have listed here so we may further assist you. As always, our goal is exceptional support. Thank you for choosing HostGator!
Hi. I think I have a dedicated IP. Could you please check whether it is so? Thank you
Hello Paul, I was able to locate that you do in-fact have a Dedicated IP address for your account "mysite.com". I have gone ahead and added a PTR record for your domain, "mysite.com" which points to your dedicated IP address "18.104.22.168". Please keep in mind that as this is a DNS change, it can take up to 48 hours to fully propagate. Once this change has taken place however your PTR should correctly display your domain name. Please let us know if you have any questions about anything I have listed here so we may further assist you. As always, our goal is exceptional support. Thank you for choosing HostGator!
So as you can see you SHOULD write to your hosting provider to see whether everything is working smoothly! :-) Hope that helps! Cheers!