Opening Part: The first paragraph of the mail writing must state the introduction of the writer. It also contains the previous correspondence if any. Main Part: This paragraph states the main idea or the reason for writing. It must be clear, concise, complete, and to the point. Concluding Part: It is the conclusion of the business letter. It shows the suggestions or the need of the action. The closing of the letter shows the expectation of the sender from the recipient. Always end your mail by courteous words like thanking you, warm regards, look forward to hearing from your side etc.
Formal communication is on the wane in modern life, but there are still times when it's the only correct way to reinforce a connection or convey information. If you're applying for a job, looking for a recommendation, or expanding your network, err on the side of formality. Don't let the slightly archaic feel of a formal business letter tempt you into using flowery, outdated language.