I see nothing in Chrome about associating web sites.
Maybe I am not understanding your problem H. What exactly do you mean when you said " I am unable to reply...."? I interpret that as a Web site has sent you an email and using your ATT mail account you type out a responding email, hit send and then you get the pop-up about bad configuration? Is that correct? And where does the pop-up come from, the ATT mail account or your computer, if you know? But on the surface it sounds like you should be talking to ATT.
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