Marketo email template moving left and stacking for outlook app mac users only

Did you try actually using smaller images in there that were natively sized to 179px or just shrinking the image with code? I think sometimes Outlook can be particular about the actual size of the image and will display images at their native size rather than their "coded size". It looks like the image here is sized to be 300px wide and put into a box that's only 260px wide, so maybe that has something to do with it?

Here's a path to a placeholder image you could use to test:

Also, I've found that sometimes it's helpful to troubleshoot this kind of stuff by putting colorful borders around the tables and cells in the HTML so you can actually see where things are lining up and get closer to the issue here. For example, it might be that the image column is (or is not) actually running 100% of the page, but it's hard to tell without having it traced. You can do something similar with background-colors too to kind of "reveal" the structure of the page as it renders in Outlook and other clients too.