Professional Email Message Guidelines
Subject Line: The subject line should concisely convey your purpose for writing. Your subject line can be as simple as "Thank You" or "Request for Recommendation"
Greeting: Even if you are writing a very short email, include a greeting. If you know the name of the person, include it. Unless you are on a first-name basis with the person, call them by their title.
Length: Keep your email as concise as possible. People tend to skim long emails, so only include essential information.
Font Style: Avoid ornate, playful, or colored fonts; these simply distract the recipient from your actual message. Avoid overusing bold and italics as well, which make an email look cluttered. Do not write in all capital letters either; this comes across as angry or overexcited in an email.
Emoticons: Do not include emoticons in a professional email; save these for personal correspondence.
Spelling and Grammar: Just because you are writing an email does not mean you should be sloppy about spelling and grammar. Edit your email carefully before sending it. An error-free message tells the recipient that your email should be taken seriously.
Closing: Sign off with a brief "Thank you," "Best," or other simple send-off, and then your name. Most email accounts let you embed a signature with your name, title, and contact information into every email. This is a terrific way to make each correspondence more professional.