1. If you have one image taking up the entire width of the email, it should be uploaded no wider than 600 px.

• In this example, I have added 10 padding on each side of the image (20 total). 600-20=580 which is what my image should resized to BEFORE uploading it to Marketing Cloud. 

If you have two columns, each with an image, they should be uploaded no wider than 300 px.

• Below, the 2 columns are split 50/50 (or 300 pixels wide). I have added 10 padding on the sides of the image (20 total). 300-20=280 which is what both images should be resized to BEFORE uploading them to Marketing Cloud. 

• In this 'newsletter' example, I have added 15 padding on each side of both images (30 total). 600-30=570/2=285 which is what both images should be resized to BEFORE uploading them to Marketing Cloud. 

Scale to Fit

Assuming this layout is set to stack, 'Scale to Fit' should NOT be checked.

This is because 'Scale to Fit' will force the image to render to the size of the device it is being viewed on. In this case, the small thumbnail image will be blown up on a mobile device and will appear pixelated (image below). 

Instead, there are two good options:

Do NOT check 'Scale to Fit' so it doesn't expand to the screen:

Or 'Hide' the image content block.

If you have three columns, each with an image, they should be uploaded no wider than 200 px.

• Below, let's look at each individual column (33% of the overall email or 200 pixels wide). I have added 10 padding on each side of the image (20 total). 200-20=180 which is what all three images should be resized to BEFORE uploading them to Marketing Cloud. 

Scale to Fit

'Scale to Fit' should NOT be checked in this situation. 

This is because 'Scale to Fit' will have the image render to the size of the device it is being viewed on. In this case, the small thumbnail image will be blown up on a mobile device and will appear pixelated(image below). 

Instead, there are two good options:

Do NOT check 'Scale to Fit' so it doesn't blow up:

Or 'Hide' the content block