Outlook 2013 User Agent

I am trying to understand the user agent string sent by Outlook 2013 when you set the folder home page url.

Here's an example with unrelated things removed for clarity:

Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; Trident/6.0; Microsoft Outlook 15.0.4420)

      

        
        
        
      

    

I have been doing some tests with F12 tools in IE and I cannot get it to duplicate the same results. For example, I can send it to send MSIE 7.0, but it doesn't send the Trident / * string. 0 at all, unless I put it back in IE10 standards mode.

Are they saying they are using Trident 6 in IE 7 compatibility mode?

Is Outlook just using whatever version of Trident it finds on the machine, or does it have its own version?

What functional support can I expect from this combination?