Of course, you can use your favourite calendar system to send the email, but what if you aren't actually going to be at your computer? It makes much more sense to allow your computer to send the email for you automatically.
To do so, you'll often need the help of an external utility or script on your computer to do the job for you. Apple Mail is great candidate for sending out automatic scheduled emails on a Mac. But Mail.app can't do this alone, it needs the help of some scripts, namely the Schedule Delivery script available in Mail Scripts, and iCal.
How to set up automatic delivery of email with Mail ScriptsFirst, get the Mail Scripts download for your version of Mail (at the time of writing, the latest version available was 2.10.2) from Andreas Amann's website. After you download it, double click on the .dmg file and let the installer install the necessary scripts.
Then open up AppleScript Editor (found in Applications > Utilities > AppleScript Editor.app) and click on Preferences in the menubar. Then in the General tab, check the box beside "Show script menu in menubar" to see a partially opened scroll icon on the menubar.
You'll have to use the Scroll to access the scripts.
Now, open up Apple mail, and write up a draft of the message you'd like to send (or may be you have a draft of the message already). Click on the scripts icon, and under "Mail Scripts" select Schedule Delivery. Fill in the desired time and date for the delivery of the mail and choose the draft that you'd like to send. And click Update.
You're set! At the right time, mail scripts will do its job (provided your computer is turned on) and save the day.
Of course, a couple of caveats: this method depends on your computer being turned on. A power outage/dead battery/accidental file corruptions/bad wifi connection/bad internet connection would mean that the message will not be sent, so choose the messages you'd like to schedule wisely.
Got a question, tip or comment? Send them to email@example.com and we'll try to answer it in a blog post!