There are stories of horror and embarrasment about people who hit the SEND button too soon on an e-mail, or who hit Reply To All instead of replying to an individual, or who sent an e-mail inadvertently to their whole address book. It's easy to type out a reply when you're emotional, and intentionally or not, hit SEND before you've cooled down and thought the situation through.
Rather than rely on yourself not to hit the wrong button, or to hit it prematurely, when you have an emotional situation, I'd suggest you write your message in Word or Google Docs, save it there, and reread it in the morning before you send it. That way, there's no chance of accidentally sending it out, and in the morning, after you've rethought and reread it, you can cut and paste it into your e-mail program.
Sometimes just writing out your thoughts is catharsis enough, and you really don't need to send the e-mail. On the other hand, you may be ready to send it as written, or ready to modify or rewrite it and then send it out. Just cool off first.

Great post. Might I add, before trying a new email feature, test it out on yourself first. I once used the "flyer" feature of my MLS system to send listing info on a new listing to my address book of lakefront buyers.
I'd never used the email flyer. It had been a long day. After sending the property info to 100+ potential customers, I checked out what the flyer looked like.
Looked great. AND IT HAD THE LISTING AGENTS INFO PROMINENTLY DISPLAYED ON THE BOTTOM!!!! Yes, shoot me now!
Gregory - having a friend read it is another great idea!
Antoinette - Yup! Always good to send yourself a tester first. Actually, if you do have to hit the Sendbutton, better to send it only to yourself.
Sharon~
Your advice reminds me of advice I got from a great teacher...My DAD, the REALTOR...he always put his correspondence away at night to be reviewed the following morning. Possibly we could put our emails in the "draft" file and accomplish the same thing...
Another habit I've gotten into is that when a message was sent to several people, if I want to reply only to the person who sent it, I try to remember to start the message by saying "Just to you..." because the few times I've forgotten to do that, the recipient has sometimes written back as if they're writing to the whole group. I also regularly do what janeAnne mentioned -- save emails in the "draft" folder because I may have something to add or that I want to edit before sending it out.
janeAnne - you have a wise father. We should do the same in our personal lives.
Marchel - I thought you were going to say that the prayer group prayed and he got money in his account.
Leanne - draft is good. It also works for when you respond to one e-mail before reading the second one from the same person on the same topic.
Tony - they're not only giving away their database, they're giving up personal information about the whole list, too.
Greg - that's good. Maybe with that review you can catch the spelling errors that didn't show up because they did spell a word, just not the one you intended.