Use Gmail filters to sort your emails as they come into your inbox. You can skip the inbox, assign the email a label and read it later.
You can schedule your emails to send at a later time. Scheduled emails may be sent a few minutes after the scheduled time.
Tired of typing the same reply every time someone sends you email with a common question? Compose your reply once and save the email as a template. Later, you can open the template and send it again with just a few clicks.