pop3 error connecting to exchange

I am running exchange 2013 with CU7.  Everything has been running fine for weeks.
All of a sudden my mailflow application that uses pop3 to log in exchange and download emails is failing.

I've already restarted the pop3 and pop3 backend processes.
I've already restarted the mailflow service on my server.
I can telnet from my mailflow server into my exchange server.

Everytime I try to test the connectivity in my mailflow program, i get "error connecting to host"

Went to DNSstuff.com and did the email test:
Successful connect: Got a good response [250 Accepted] (took 0.680 seconds

But then checking the pop authorization on DNSstuff, I get this message:
Test Status:  failed message send with: failed cx open with: ssl CONNECT failed with: no SSL lib error; sys lib says: Connection reset by peer

Any ideas how to solve this issue?
DanNetwork EngineerAsked:
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DanNetwork EngineerAuthor Commented:
I just tested the "test-popconnectivity" and it failed.

So where do I even begin to work on this issue?
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DanNetwork EngineerAuthor Commented:
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