1). After you have finished typing your email, click the drop-down arrow attached to the send button (circled in red below).

2). A drop-down menu will appear with a few different options (shown below). Select the “Schedule send” option (shown circled in red)

3). The Schedule send menu will appear (shown below). Select the “Custom time” option (circled in red below).

4). The Set custom date and time menu will appear (shown below). Select the date and time that you would like the email to be sent. Once you have set the desired date and time for the email to be sent, click “Send” in the bottom right of the menu.

FAQ

What if I need to change the date that the email is going to send or modify the email?

After you have scheduled the email to send, it is placed in the Drafts folder. It will have a red prefix of [Scheduled] rather than the usual [Draft] prefix (shown below).

Once you have located the email that you’ve scheduled, you can click on it to display the message. There will be a banner at the top of the email indicating that it is scheduled to be sent and the date/time you’ve scheduled it for sending. At the far right side of this banner, there is a button to “Cancel send” (shown below)

Note that the Cancel send button won’t delete the draft but cancel it from sending at the scheduled time and convert it to a standard draft. It is also worth noting that if you will have to click the Cancel send button if you are trying to modify the contents of the email, even if the date and time you’d like the email to send is the same.
 

Once you have click Cancel send, you can modify the draft of the email and go through the Schedule send process again with the desired date and time you would like the email to send.