Hi all,

We are hoping to roll out a new email design for our marketing emails. We've had the email coded by external developers since we don't have the resources in house. We then started to a/b test the new email design against our old design before rolling it out more broadly — using the same content for both designs, just the look and feel was different. While the CTO was higher for the new design (which is great news), the open rate was significantly lower for the new design — 16% vs 20%, several hundreds of opens in difference. We've tested this three times and have received the same results each time.

What's puzzling is that the subject line, preheader, from name, IP address etc. were exactly the same for both variances. Any idea what might influence the significant drop in open rate? Might this have something to do with the new email code? Could it be so "poorly coded" that it lands in people's spam folders?

Two more things to note:

  • The delivery rate was the same for both email designs
  • Unfortunately, we do not have a tool like Returnpath right now but judged by the lower open rate I'm assuming the inbox placement was significantly lower for the new design.
  • One thing to note is that, upon digging in deeper, we are seeing the drop in open rate mostly for Gmail users

Any insight would be much appreciated!