Email Cropped in Outlook
Outlook 2007, Outlook 2010, Outlook 2013 and Outlook 2016 use the Microsoft Word rendering engine, which have also inherited theMicrosoft Word image height limit of 18 inches.
So if your email images are higher than 1728 pixels (approximate 18 inch), Outlook will crop the upper portion from the top-down.
Solution
If your newsletter is an image higher than 1728px, please try to slice it into smaller image slices in Photoshop.