A drawback of this technique is that it does not support responsive images. This is because the margin offsets of the hotspots are specified in pixels. The images should not be made to shrink or expand to its container or the hotspot coordinates will be off.

However you can still leverage interactive hotspots in your responsive designs with a combination of the following tweaks.

• Use media queries to re-adjust both the image size and hotspot coordinates on mobile.
• Use scalable images in the fallback image so your hybrid/spongy email will still scale appropriately in the Gmail mobile app.
• Use a narrower base image so that the email has room to shrink in a mobile client.
• Use large fonts in your email so a fixed width email will still look good in mobile.