If you have some news that you don’t want to share immediately,
Outlook lets you defer delivery until a specified time. Write your
email, then switch to the Options tab and click Delay Delivery. This
opens a requester with a “Do not deliver before:” field; enter a date
and time, then click Close. After you hit Send, the message will be held
until the specified time for sending. If you’re using an Exchange
server, you can now close Outlook; if you’re using POP or IMAP you’ll
have to leave the application open until the specified time for delivery
has passed. If you have some news that you don’t want to share immediately,
Outlook lets you defer delivery until a specified time. Write your
email, then switch to the Options tab and click Delay Delivery. This
opens a requester with a “Do not deliver before:” field; enter a date
and time, then click Close. After you hit Send, the message will be held
until the specified time for sending. If you’re using an Exchange
server, you can now close Outlook; if you’re using POP or IMAP you’ll
have to leave the application open until the specified time for delivery
has passed. 
