I recently found myself re-writing similar emails constantly: welcome emails, follow up, introductions, RSVP etc. Sometimes I would spend the time looking for an email I had written in the past and then would use that as my base, but I realized I was spending too much time erasing the information that didn't relate to my current email.
My new solution is to put these template emails into the signatures of my email accounts and so far it has saved me a lot of time.
1. In Mac MAIL , go to the top menu bar and select "preferences" under the "mail" menu option.
2. Once there you will get to your mail preferences. Select "Signatures" , the second to last option on the "Accounts" pop up window, shown below.
3. In the "Signatures" section, you will have the choice of adding new signatures by pressing the "+" sign at the bottom.