We like to keep a copy of the exact email or note sent to a constituent as a receipt/acknowledgment. There have been cases where a constituent claims to never have been acknowledged and we can send a copy of the time/date stamped email to them to show when they should have received the email, keeping our credibility intact. Also, as our emails show from our principal, he sometimes asks for copies of the email sent to a particular constituent so he could be set up as a recipient of the email as well or we would have a copy we could send him as he requests it. This could be done in the email set up screen easily.