Mac OS X Mail client config

[rose_in_pa]

Hi,   

I'm running OS X 10.11.5 (El Capitan) and for about 2 months now the Mail app has stopped working with a bad password message from pop.verizon.net.   error =  "Unable to verify account name or password"   

Yes,  I CAN authenticate using netmail.verizon.net and it works fine.    I have:

• Deleted the Mail account,  cleaned out the keychain values.
• Used different formatting of my username    <name>      <name>.@VERIZON.NET
• Verified all of the server names/ports and security SSL config stuff and sucessfully pinged them.
• Deleted the mail account from the OS X Settings panel and tried to recreate.
• Even tried the old pop servers of incioming.verizon.net

What drives me CRAZY as this was working for YEARS until about 2 months ago.  I've seen and followed the plethora of community pages which just indicate the server name, port, etc....  

I'm not married to the MAC OS  X Mail client as I even tried Thunderbird after being on the phone with Verizon Tech Support for 2 hours.  We never could get it working and I needed to run out.

Does anyody have any ideas or can they reccommend a Mail client that I could use?  I'm so tired of going through the browser and all of that typing.    

TIA,

Cliff