With the latest release of MailChimp, we’ve added the ability to optimize your send time. Within the send time scheduling section of the app you’ll find a recommendation hand-delivered to you from MailChimp’s Email Genome Project. It recommends the optimal send time out of the next 24 hours from the selected delivery date. The send time recommendation is determined by clicks, the idea being that your predicted time will maximize your click-through rate.

Send time optimization’s basic mechanics

At a high level, send time optimization looks at the send and click data for your specific list of subscribers and makes a recommendation based on their past engagement times.

But there are a few nuances that I want to make clear up front:

• Since MailChimp has 4+ million users, we look globally at each email address’ engagement in deciding the best time to send to your list. Chances are the email addresses on your list receive email from other MailChimp users. That means that even if you’ve never sent to your list or only sent a few times, we can still provide a recommendation.
•  The recommendations are for a 24 hour period and change dynamically as new data rolls in across the MailChimp ecosystem, so recommendations will change over time.
• The send time recommendation is weighted toward the most engaged readers on your list. After all, why would you want to optimize for the dead weight on your list that never opens?
• The model doesn’t simply choose the time slot with the highest number of clicks, but rather a time slot with an excellent click-to-send ratio. A time slot can have a ton of clicks simply because it has a ton of sends, and that’s not a great metric.
• Sends from previous time slots are factored into the calculation as well. For example, in the charts below, the send and click distribution is more preferable for a 6 p.m. recommendation in the second chart than in the first. Why? Because in the top scenario, there are plenty of clicks at 6 p.m., but since that’s when the email is actually hitting the inbox, the send time is driving the click time more than in the second chart. There, we’ve got a clear delay between send and click, implying that this is when subscribers are entering into the content to engage because it’s convenient for them. In both cases, 6 p.m. is naturally more preferable than 3 p.m., when there ain’t nothin’ going on.

Give it a shot

Just because there is no global best send time to rule them all doesn’t mean there isn’t a best time for your list. And send time optimization helps you figure that out.

The feature is only available to paid accounts, but if that’s you, give send time optimization a shot and see how it performs versus your previous campaigns. But keep in mind, the primary driver of engagement for your list is you: your content, your industry, the list you’ve uploaded. Send time optimization is icing on an engagement cake—or icing on an engagement meatloaf if your list is hemorrhaging. If someone doesn’t want to open, they won’t open, regardless of delivery time. However, when someone wants to open, this model helps line up the send with their availability.

Happy sending!