Archiving Announcements
You may decide, for instance, that you should announce an upcoming campus event every three or four days for two weeks before the event, with a final reminder the morning of the event. By saving your messages, you can be sure that you are sending accurate information each time you send it. And you can be sure that you’ve met your schedule.
Moreover, if someone loses one of these "general distribution announcements" and asks you to repeat the message, you have a copy in your email archive to send instantly.