Studies show that on average, 20% of email goes undelivered. That means that for every 100,000 emails you send, 20,000 emails end up in the junk folder or are marked as spam. Depending on your cost per email and your actual delivery rate, you could be losing a lot of money. And depending on customer expectations, you could be leaving a bad impression on users that are expecting to hear from you.

What if you focused on getting those 20,000 emails delivered rather than trying to find 20,000 new customers? Interesting thought right? Let’s do a quick calculation. For arguments sake, let’s say on average 10% of your email respondents convert to a sale and that the average sale price is $20 per email. If you send one million emails per month, this would be the result based on the email delivery rates provided below.


80% Delivery

90% Delivery

100% Delivery

Emails Sent




Emails Delivered




Clicks (5%)




Conversions (10%)




Total Revenue ($20/order)





With only an 80% delivery rate, you are losing $20,000 per month or $240,000 per year. You no doubt  have email revenue goals that you have to meet and when they fall short, you focus your efforts on trying to acquire new users or sending more mail to existing customers. This can be expensive – especially when you are investing dollars to find new customers (or annoying loyal customers with increased frequency). So instead of finding new customers, allocate some resources to finding missed customers. By improving your email deliverability, you can improve your overall email ROI using your existing list and optimizing for email list growth.

Jillian Wohlfarth
As SendGrid's Director of Content, Jillian is responsible for ensuring that SendGrid provides valuable thought leadership content through the blog, whitepapers, webcasts, and more. When not writing and editing, you can find Jillian frequenting Denver restaurants in search of the best queso.