I would like to share with you what we are experiencing in the last month. The thing is that after we changed our email domain (and SSL cert, of course) we are sharply receiving a lot less clicks on the mirror link than we used to receive before (they are now about a third of what used to be)
The domain we've moved to is shared with our website, and the former one was exclusively for email marketing, with no other content served.
Would you have any explanation for this to happen? I can only think that we are more trusted now by security systems, but I'm not sure this argument can only apply to the mirror page link.