Send time optimization

Image: Send time optimization

Send time optimization detects when recipients actually check their inbox, and sends your message to each individual at a time that matches the rhythms of their life. As a result, your email appears at the top of the inbox. Send time optimization ensures that your mailing is received during key, attention-grabbing minutes, and does not get lost at the bottom of the inbox with a bunch of other messages.

Send time optimization can increase the open rate for your messages by up to 25 percent. As a marketer, you benefit from the undivided attention of your recipients, which increases your return on investment.

Image: Inbox

Why should you automate optimization?

Many marketers follow three simple rules to determine the best send time for their campaigns, based on the findings of various studies.

  • Tuesday is the best day to send out mailings. Thursdays and Wednesdays are the next best days (the response rate by recipients is the highest in most industries on these days).
  • Around 10 AM is better than early morning, afternoon, or evening (recipient responses are the highest at this time for most industries).
  • Workdays are better than weekends.

Image: Best send time

Although the rules are based on many studies and billions of data sets, they are derived from average values, and do not consider each recipient's preferences (and also do not apply to every industry). Do not rely on average values or the assumption that "one size fits all" – rather, learn about the particular lifestyles of your customers. Adjust your send times to accommodate the preferences of your recipients.

How it works

Send time optimization creates a personal profile for each recipient then analyzes their response behavior. Machine learning: The longer the customer relationship, the more accurate the optimized send time. And, if a recipient changes their behavior, their profile is updated accordingly.

The self-learning algorithm also analyzes click behavior and message opens, because opens by themselves do not provide sufficient evidence of whether a recipient is interacting with their inbox.

Around 70 percent of users now own a smart phone, and reach for it an average of 88 times a day to check their inbox or open a message, if only to reduce their unread message count to zero. When users check messages, they are much less likely to read emails in depth or to follow interesting links. Therefore, send time optimization considers the click behavior of recipients to determine when they are focused and responsive, not just clicking off a notification.

Image: Optimal send time


  • Increase the open rate for your emails by up to 25 percent.
  • Decrease likelihood that your message will go unnoticed.
  • Your advertising messages are perceived as less obtrusive.
  • The service adjusts to the recipient's behavior, and changes the send time when a recipient changes habits.
  • Send time optimization is automated.
  • It has a low learning curve. The feature integrates with the familiar, standard features of Optimizely Campaign.
  • Virtually infinitely adjustable for up to 7 days.
  • A fallback time can be set for new recipients for whom behavioral data is not yet available.
  • Available for Smart Campaigns Optimizely feature for sending out one-shot-campaigns, such as an event invitation or special Christmas offers. (including A/B tests).
  • Analysis function to evaluate individual send times.

Setting up time optimization

Send time optimization is available only for the Email channel.

To set up send time optimization, contact customer support. The feature as an extension: