By default, all images are linked to from an email and are therefore not included in the body of the email and do not increase its size. These images will sit in the '_images' folder and are therefore hosted by Vuture.

If you use the Embed Images feature, then images are included in the body of the email and you should take care with image size. Vuture will automatically optimise these when you crop them in, but you should limit the total number.

In summary, GIFs and including images should not cause deliverability issues.