Images show as Red X in Outlook: (It may effect all images and all employees):


Outlook cannot show images located on https

This is caused by a special setting in your Internet Explorer (IE). Even if IE isn't your default browser, Outlook relies on some IE settings.


Reset Internet Explorer to its default setting.

Go to Tools > Internet Options > Advanced (tab) > Reset button (bottom of window). 

Or specifically, untick this setting: