I have to go to the post office if I have to send a letter.
It is necessary to write the return address. With it's help we can learn from whom the letter is.
It is very important to write addresses correctly. If the address is wrong we can't receive the letter.
If I want to recieve the letter from friends I have to write the letter to them, ask many questions and ask to answer the letter.
It is pleasant to receive letters or holiday postcards from people whom you like and who are dear to you because we feel their love possitive attitude to us.
Sometimes it is necessary to send a telegram. For example, when we are pressed for time to send a letter. To send a telegram I phone to the post office call my address, address where I want to send a telegram and the subject of it.