Unable to find out why we can't send email to Verizon customers

All email sent from our email domain has been rejected by Verizon with the error message stating:

571 Email from xxx.xxx.xxx.xxx is currently blocked by Verizon Online's anti-spam system. The email sender or Email Service Provider may visit http://www.verizon.net/whitelist and request removal of the block. 150313

I have submitted numerous whitelist requests and get no response. We are a school and only email to students and prospective students. We are not blocked by any other service and our email reputation is good. What do I need to do to at least get an answer from Verizon as to why they will not unblock us?

Re: Unable to find out why we can't send email to Verizon customers
Champion - Level 1

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 look in the middle, right at the top where you will find an area titled "My Support Cases". You can reach your profile page by clicking on your name beside your post, or at the top left of this page underneath the title of the board.

Under “My Support Cases” you will find a link to the private board where you and the agent may exchange information. 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, at the top of your support case there is a drop down menu for support case options. Open that and choose "subscribe".

Please keep all correspondence regarding your issue in the private support portal.