Trouble Whitelisting E-mail Server IP

[vtxrocketeer1]

In the hopes of attracting Verizon problem-solvers, I'm posting here as a Verizon customer and owner of a small business.  I own my own business domain, but my e-mail server is owned by a parent company and all outgoing e-mail goes through that company's e-mail server.  

  All of my outgoing business e-mail to Verizon addresses suddenly started to get blocked today by Verizon anti-spam.  I listed my e-mail provider's IP of the e-mail server, following Verizon's suggestion to submit it for whitelisting.  Twice it was rejected with the following reply: 

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.

  So far as I know, the IP is static.  Also, the IP is not blacklisted (verified this at http://whatismyipaddress.com/blacklist-check).  

My e-mail host threw up its hands, staing that my 'clients' should pick a different e-mail provider, i.e., not Verizon.  Uh, no.  Any ideas about getting on Verizon's WhiteList?

Thanks.