Dave Marshall is the CTO of Childcare.co.uk and he said, “One of our most important and critical emails is the notification when a parent sends a message to a caregiver. We received numerous complaints about people not receiving these emails when we sent them. This was a problem for a number of reasons, so we started investigating other ESPs.”
I was shocked to see Postmark open rates were an 11% improvement over SES in our test. Needless to say we started sending all of our transactional email through Postmark.
Dave asked his friends on Twitter if they had any data comparing delivery improvements between Email Service Providers. During that conversation Postmark came up several times and Dave decided to test delivery between Postmark and Amazon SES.
To test delivery Dave decided to compare open rates for one email. “The test was pretty straight forward. We decided to look at open rates for our New Message Received emails. I had them go out with a 50/50 split between Postmark and SES. Everything was sent using our own code without any particular split testing library.”
Once everything was in place Dave checked in to see how each provider performed. “I was shocked to see Postmark open rates were an 11% improvement over SES in our test. Needless to say we started sending all of our transactional email through Postmark.”