Error in CF Admin mail test

Hello all-

I've got a new install of CF 11 on Windows Server 2012 R2.  For the first week or so everything was fine, but after a while my email stopped going out.  I looked at the pages generating email, and there was a CF error.

So I went to the admin to verify the connection- Boom- error in the admin!  Every time I attempt to verify my email settings, I get an error.

I do not believe there were any changes made to the server between the time email was working, and when it died.  Potentially a Windows Update, but that is about it.

Any ideas on this one?

Thanks - Karl