Emails are generally shorter than letters. As they are often written quickly, in response to a request or question, they may contain only a few lines. Informal English, abbreviations, and absence of standard salutations are common when you write an email. Emails may contain the following elements: -subject line: This shows the reader the exact subject of the email. (salutation): This is optional. Some people start with "Hi", others with the first name of the reader, or others with no name or salutation at all.