ANDREW HALL
456, X Street, Y Avenue
Philadelphia, PA-19103
(123) 456-7890
[Subject: Normally bold, summarizes the intention of the letter] -Optional-
Dear Andrew hall,
I am sorry that we sent you the wrong set of trees against your order for short trees. Due to mixing of orders we sent you dwarf trees. We are immediately sending you a replacement. You can keep the previous trees with you only. We appreciate your continued patronage.
Sincerely,
John smith