"We are uanle to whitelist your IP" doesn't suggest a solution

To our previous post, Verizon's Tech Chat person responded that they are not able to whitelist our IP with out mentioning any clear reason. This is not helping us ro resolve the issue. Appreciate if anyone can suggest some solid solution

We have verified and ensured that every settings on our server are correct: 

1) Our IP is not in any of the public black list 

2) we have proper and valid spf and PTR in place

3) And we are not sending spam emails

However, our IP address got blacklisted by verizon.

It is being blocked from sending mails  to any customers who have a verizon account.

We tried the whitelist form several times, every single time receiving the same canned response everyone else gets:

"After investigation, Verizon Online Security has determined that e-mail from your IP address will not be allowed access to the Verizon Online e-mail domain due to one or more of the following reasons: Your IP has been blocked because of spam issues or because your ISP indicates that it is dynamically assigned Once you have addressed any security-related issues on your network, you should contact Verizon Online Security via this form. At that time, we will work with you to restore normal e-mail traffic or to take other action as we deem appropriate."

Re: "We are uanle to whitelist your IP" doesn't suggest a solution
Contributor - Level 1

Hi Srirama,

Your issue has been escalated to a Verizon agent. Before the agent can begin assisting you, they will need to collect further information from you. Please go to your profile page for the forum and scroll down the page to an area titled "My Support Cases". You can reach your profile page by clicking on your name located above your post, or at the top right of this page.

Under "My Support Cases" you will find a link to the private board where you and the agent may exchange information. The title of your post is the link. This should be checked on a frequent basis, as the agent may be waiting for information from you before they can proceed with any actions. To ensure you know when they have responded to you, you may subscribe to the case. At the top right of your support case there is a gear icon which provides a drop down menu with support case options. Click that and choose "subscribe". Please keep all correspondence regarding your issue in the private support portal.