Why do you use HTML5 if you haven't tested it with all browsers? On top of that, you can't even identify the browsers correctly thinking that IE11 is an old browser and that I should upgrade to the newer IE9. Horrible Q/A work on this one.
I tested using our site on IE11, and did not get any notification that I was using an outdated browser. I apologize if you are running into these notifications. I would like to help you so that these do not appear. Can you please go through the steps in this FAQ to optimize IE for use with Constant Contact. Also can you check the Emulation mode of your browser please? Here's how to do that if you are not familiar.
Press F12 to open the developer tools. (You can also click the gear towards the top right of the window, then go to Developer Tools).
Click the down arrow until you see the Emulation icon (a desktop screen and a phone)
Under Document Mode, make sure that this is set to Edge, 10 or 9 (These are the versions we are compatible with).
Once this setting is changed the screen will adjust automatically and might flash briefly. You can then click the X in the top right corner of the developer tools icon.
Once you go through those steps, if you are still seeing this message please let us know so we can do further testing and troubleshooting.
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