Does Outlook for the desktop really still use Internet Explorer?

Applies To: PoliteMail Desktop  □ PoliteMail Online □ PoliteMail O365

Version:  4.9    5.0    5.1+

Oddly enough, yes.  Even if you use Edge, Firefox or Chrome for browsing, the IE11 component is always used inside of Outlook, even though the standalone version of Internet Explorer has been deprecated by Microsoft and you don't think you even have it installed.  Here's how you can tell:

>>> Technical Details Ahead <<<
  • Find an email you received with some graphics in it.  For security, Outlook will probably show a banner at the top of your email saying it may not display all pictures.
  • Click on the banner and you’ll see an option to ‘View in Browser’.  If you click on it, you’ll probably just see a bunch of html on your screen, but look at the url and you’ll see it ends in .mht.

Mht files are an old file format that combines all the separate images and other elements of your email into one file, kind of like a .zip file.  Mht files are not supported in other browsers since version 80 or so because since the browser can’t check each component individually, they cannot see if everything is safe.  Now, as an aside, you can change a setting in Edge under ‘compatibility’ to allow sites to be reloaded in Internet Explorer mode” to see the actual message, but the point remains, Outlook for the desktop renders messages in Internet Explorer.

This is a problem, because IE is… not great.  Microsoft deprecated it for a reason.  It’s old and slow, and as a result slows down PoliteMail. especially when viewing Metrics reports as IE simply cannot keep up.  In PoliteMail, our Reports are actually HTML pages, and so, when loading with IE 11 in Outlook, can become terribly slow as the old Internet Explorer browser – Outlook’s default - just can’t keep with the dynamic data loading PoliteMail is doing to display the analytics. 

So in the new v5.05 update, PoliteMail has included its own modern browser component, powered by WebView2, a control which displays HTML content in Edge, which is powered by Chromium.