When’s the Best Time to Send Your Emails? Smart Send Time Has the Answer.

Send Time Optimization

One thing all email marketers want to know is, “When is the best time to send my emails?” Klaviyo’s  Smart Send Time feature answers that question for you. 

What is send time optimization? 

Send time optimization automates what used to be the slow, difficult process of identifying the best time to send your emails.

Figuring this out on your own takes a lot of testing, reporting, iterating, and most importantly, time.

The new Smart Send Time feature in Klaviyo automates this process so all you need to do is click send. 

Klaviyo’s Smart Send Time uses our custom-developed smart optimization technique to learn the behaviors of your email recipients to tell you exactly when to send future messages to maximize your open rates.

It will also continually adapt to any changes in your customers’ behavior, so the best time to send your emails will automatically change as your customers’ behavior changes. 


How does Klaviyo’s Smart Send Time feature work? 

To get a full view of how this feature works, we’re going to use Smart Send Time to find the best send time for a fictional ecommerce business called the Corner Three. 

Corner Three sells basketball gear and accessories. The brand wants to let subscribers know about a new style of basketball socks through a promotional email.

Normally, Corner Three sends its promotional emails at 10:00 a.m. and uses the schedule by recipient time zone feature so each person receives the email at 10:00 a.m. local time. But this time, Corner Three sees the Smart Send Time option and wonders, “Is 10:00 a.m. truly the best time for us to send our emails?”


send-time-optimization feature in Klaviyo


Corner Three selects Smart Send Time and sees its first campaign email will send over a 24-hour period.

Why? To get an accurate reading, Klaviyo needs to learn about how people in Corner Three’s list interact with emails at all different times of the day.

To do this, the first campaign sends at regular intervals over a 24-hour time period to check open rates across the entire day.

There’s a tradeoff here—some emails will be sent at suboptimal times with lower open rates (like 2:00 a.m.), but Corner Three will know its optimal send time for all future emails.


send-time-optimization-report in Klaviyo


Corner Three’s campaign goes out to its main newsletter list. A couple of days later, after all the open and click information has been collected, Klaviyo automatically analyzes the data.

The next time Corner Three sends its standard weekly newsletter to the same list, the brand will have the option to send it at the optimal time—6:00 p.m.

Based on the learnings from the initial 24-hour send, Corner Three now has a send time it can use to maximize its email engagement going forward.


send-time-optimization-ready to send option in Klaviyo


Once Klaviyo finds the best send time, the learning doesn’t stop learning there. Each subsequent time Corner Three sends to this list using Smart Send Time, the model will test the result and ensure the send time is still optimal.

To do this, Klaviyo sends the email within a four-hour window centered on the optimal send time.

In this case, since Corner Three’s optimal send time is at 6:00 p.m., Klaviyo will send some emails at 4:00 p.m. and some at 8:00 p.m. By continually collecting engagement data at different times, Klaviyo will detect any changes to the optimal send time and shift the time automatically.

By using Smart Send Time to send just a couple of emails, Corner Three learned the best time of day to maximize its email engagement.

Over the course of the next month, Corner Three started sending its campaign emails at the optimal send time and saw a 12 percent increase in open rates! 

Throughout our testing with customers, brands that sent their emails using the newly optimized send time feature saw their open rates increase by 10 percent on average.

By allowing Klaviyo to automate the data science part of the process, you get a statistically optimized send time without spending hours of time figuring it out yourself.  


Try Klaviyo free to start using Smart Send Time today or boost your email engagement and own your growth. 


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