How to supress the warning window when moving from Https to http

[dluke]

I have seen that in other email sites when moving from https to http the warning window does not pop up where it warns you that you are going to a nonsecure site and whether you would like to proceed.

How does this work fopr the sites where this message is suppressed and it smoothly moves from http to https.

Thanks and hoping to hear from you guys.

DL :)

[Fang]

They have their own certificates, not a shared one.