In subject, the general idea of this E-mail should be concise and clear to understand. Sometimes it can just be a word, such as greetings. A noun phrase or a sentence can also be served as a subject, but it should not be too long.
B.
Only the first letter in the first word or some proper nouns must be capitalized in subject.
C.
You can also put “URGENT” or “FYI”(For Your Information)at the beginning of the subject.
D.
It should flush with the left margin. Then put a comma or colon after that.