2365 S Mayfield Ave
Chicago, IL 60652
[Subject: Normally bold, summarizes the intention of the letter] -Optional-
Dear Paul smith,
Regrettably, I cannot accommodate a meeting with you this coming Tuesday to talk about details of your upcoming event. I have previously been scheduled for various engagements this entire week. I will be available on Thursday and Friday next week, so just call my secretary for an appointment. I look forward to meeting you then.