Images can be resized in the following ways:
Option 1: Right in your email content:
1. Go to the Email Content Editor.
2. Click to select the image in your email content.
A black border with eight “handles” or small white squares will appear around the image when selected.
3. Place your mouse on one of the eight handles.
4. Click and drag to make the image larger or smaller.
Making a small image larger can cause pixelation which can make the image look fuzzy.
Option 2: Use Image Properties > Dimensions
Go here for instructions on resizing using Image Properties
Option 3: Use Image Library > Edit Image > Alter
Go here for instructions resizing using Image Library