Whether or not a recipient will open your email depends largely on what the subject is. Unfortunately, spam emails have made it even easier for people to ignore or just delete emails they can’t make an immediate connection with. What gets your mail treated as spam, unimportant, frivolous or insignificant begins at the subject line.
It may seem like an easier option to just leave the subject field blank but that’s a terrible idea. The subject of an email is meant to give the recipient fore-knowledge about the content of the mail.
Never leave the subject field of an official email blank. The subject field should contain a one line summary of the content of the mail. It should be straight to the point and free of embellishments and superlatives. On the other hand, it should not be cryptic or vague, like “The thing you asked me to send.”
It can be a word or phrase that best describes the body of the email, like “Proposal Letter,”“End of Year Report” or “Follow up on Friday’s Meeting.”
It is tempting to write out the subject of a mail in all capital letters. However, writing in all caps is the equivalent of screaming. Unless you are sending an angry email an all caps subject line is best avoided.
You may begin each word with a capital letter or simply stick to a sentence case. Some people go for all capital letters to give the impression of urgency, if this is the case, it is better to begin the subject with “URGENT” or “Urgent” followed by the summary of the content.
Remember to keep email subjects short, straight to the point and relevant to the body of the mail.