Send later in Mac not available

I have watched tutorials, read help articles on apple and practiced on other OSs (ahem - Microsoft). The ability to compose an email then send it at a later time and or day seems like it should be as easy as a few clicks. But I can't seem to find the option on my Mac. Any help is much appreciated!! I'm trying to send time sensitive emails that I don't want buried in the recipients inbox when the time comes to need it.