Difficulty with terminating a verizon.net email account

[JGM-CHM]

Way back in the day when we signed on with Verizon DSL, we obtained a Verizon.net email address which was streamed through Yahoo. 
A few years later, we obtained email addresses through our business website domain and no longer needed our Verizon.net address. However, our outgoing mail was still connected to outgoing. verizon.yahoo.com to work correctly. 
We stream our email through Microsoft Outlook 2007 , which  worked great until April 8.  At that time,  outgoing mail stopped working. 
Neither Verizon or Yahoo has been able to help correct this problem.

We have not used our verizon.net email in 10 years and want to delete it. 
However, when I use the Yahoo website and attempt to complete the online form for terminating the account, the form does not recognize my verizon.net email address as a valid address. 
I am beyond frustrated and just want to eliminate all traces of this account from my Microsoft Outlook 2007 settings, but until I delete this email, I cannot. 
I appreciate any assistance with this matter. 
Thank you. 

[LawrenceC]

Hi JGM-CHM,

Your issue has been escalated to a Verizon agent. Please check your Private Message Inbox for a message from Verizon_Support. You can find your Inbox by clicking on your username at the top right corner of this page. Please direct all correspondence concerning your issue to the agents who will be assisting you privately.