# Optimize The Sending Time Of An Email Delivery

Send time optimization automatically schedules email messages to send at the time of day, and optionally the day of the week, a contact is most likely to open emails from you.

You should avoid using send time optimization for time sensitive deliveries where you want to control when email is sent.

Send time optimization is calculated for each contact based on their open history. If there are no opens recorded for a contact, the delivery time you selected using the Send message now or Send at this time radio buttons is used. If the contact has:
• 1 to 10 recorded opens: the email is sent at the open time that occurs most frequently in a contact's open history. So if a contact has opened five emails and two of those were opened at 8 PM. and the other three emails were open at 1, 2, and 4 PM. the email is sent at 8 PM. (This is the statistical mode.)
• 10 or more recorded opens with a standard deviation of less than 5: the message is sent at the average of all of the open times. This may or may not match one of the recorded open times. For example, if 10 opens were recorded for a contact and five of the opens were 9 AM. and five of the opens were at 11 AM. then the email will be sent at 10 am. (This is the statistical mean.)
• 10 or more recorded opens and the standard deviation is greater than or equal to 5: the email is sent at the open time that appears most frequently in a contact's open history. For example, if 10 open times were recorded for a contact, and 3 of those times were 8 AM, and the remaining 7 times were other unique times of day, then the email is sent at 8 AM. (This is the statistical mode.)
Standard deviation is used to quantify the amount of variation in a set of data. The higher the standard deviation in a contact's opens history, the less effective using the average of the opens to optimize send time is. This is why we only use the mean, or average, when the standard deviation in a contacts open history is less than 5. Sending emails at the average open time when the standard deviation is above 5 would result in more of a random than a targeted send.

The send time optimization calculation for a contact is refreshed daily.

Day optimization is based on the day of the week that the contact has the most recorded opens. If there is a tie between two days, then the first day found is used.

To use send time optimization:

## Procedure

1. When scheduling a message, scroll to the Delivery Scheduling are and choose
• Send message now if you want the message to be sent as soon as it is scheduled.
• Send at this time and enter a date and time if you want the message to be sent as a specific time.
The option you select will be used for contacts that do not have sufficient open record data, including new contacts.
2. Check the Optimize Time of Day box.
For each contact, the Optimize Time of Day option will schedule the delivery so that the email arrives in the contact's inbox at the time of day the contact is most likely to open emails from you. This delivery may appear in your outgoing deliveries for up to 24 hours.
3. Optional: Check the Optimize Day of the Week box.
For each contact, the Optimize Day of the Week option will schedule an email message to send on the day of the week the contact is most likely to open emails from you. On that day, the email will be sent at the contact's optimal time of day. This delivery may appear in your outgoing deliveries for up to a week.