Based on the goal of the letter that you’re sending, you choose the one of the three correspondence letters approaches.
1- Direct approach: you can use this approach when you want to transmit good news to your reader. The main and only rule is to start directly with the good news, and it’s recommended that you leave goodwill and a friendly frame in the mind of the reader at the last paragraph.
2- Indirect approach: you can use this approach when you’re transmitting bad news to the reader or to say no. the main rule is to put the bad news in the middle of the letter, by putting a buffer between the reader and the bad news, the reader must begin and ends with positive message.
3- Persuasive approach: Getting the reader to do what you want, to accept what you say, or to agree with you. In the persuasive approach the letter starts with a promise or imply some benefit or reward for the reader, then describe the service pr the product, and finally ask for action.

