456, X Street, Y Avenue,
[Subject: Normally bold, summarizes the intention of the letter] -Optional-
Dear Jack Martinez,
I wish to inform you that we will not be able to have our meeting at11:00 a.m. on Monday, May 6. This is because a new policy has been announced by our office which does not allow employees to travel for the upcoming three months. We will have to commence our business either through email or phone from now on. I am confident that this new policy will not effect my performance on any level and you will receive the best quality service.