problems with security certificates
 

Recently, after many years without this problem, certain emails I receive
regularly (such as from Mercola.com), have begun triggering a Security Alert
popup window, which tells me there is a problem with the security
certificate. I go through the routine of View Certificate, install
certificate, etc..., but it never sticks. And when I try to clear this
popup window by clicking on the YES choice, sometimes I have to click 10
times because it keeps popping up a new identical window, and then finally
it will go away. But next time a new email comes from one of these sources,
up comes the Security Alert window again!

This problem only happens when I choose the particular email. How can I stop
this from occurring. These emails are from good sources, and I've never had
a problem with them. Any advice for me?

John