Business letters are not written to businessmen only; we write these to officials (e.g. postmaster, health inspector, newspaper editor, bank manager) also. A good business letter must be brief and clear. Say what you want to say and no more, no less. Here we are with How to write formal business letter format with a few hints to write business letters.
A business letter contains the ‘inside address’. This is the same as the address on the envelope, but it is written against the left-hand margin. For an example see the first letter below.