There are many reasons you might want your email to arrive at a particular time, like wanting your mail at the top of someone’s inbox when they start work. You can do this in Outlook by scheduling your messages.
Before we go any further, we need to add a couple of caveats. First, sending an email at a particular time does not guarantee that it will arrive in your recipient’s inbox at that time. There are many steps between you sending an email and the email appearing in someone’s inbox. While you can generally assume that a message sent at 8:30 am will be in someone else’s inbox within a minute or two, don’t rely on it for critical delivery. The second caveat is that this only works for the desktop Outlook client, not the Outlook web app.
How to Schedule a Message in Outlook
With that out of the way, let’s schedule a message in Outlook. The good news is that you don’t need a 3rd party add-in to do this; it’s baked right into the Outlook client. Create your new mail as normal, then in the ribbon click Options > Delay Delivery.
Set the date and time you want your mail to be sent, and click the Close button. And that’s all there is to it. Send your message, and it will sit in your Outbox until the date and time you chose. Outlook will then send the message.
An important thing to remember: Outlook can only send emails when it’s open. If the date and time you’ve chosen rolls around and Outlook is closed, Outlook won’t send the message until the next time you open Outlook. But if you work in Outlook all day and you want to schedule a message within working hours, this isn’t a problem.
Source : How to Schedule An Email in Outlook
