Email is the communication of convenience. It's faster than sending a letter and less time consuming or intrusive than a phone call. It is often the first line of communication between individuals both personal and professional, and on occasion their only means of communicating with each other at all.
Which is why netiquette is so important to exercise. Since email became available to everyone, we've all experienced moments of embarrassment or aggravation as a result of poor manners online, whether committed by oneself or another messenger.
If you want to avoid looking unprofessional or causing your mail recipients irritation online, then keep in mind these few simple rules.
First and foremost is the subject line. You wouldn't be writing an email in the first place if you didn't have something important to say. Don't give your email an arbitrary subject line. The person that opens your email needs to know what they're going to be looking at before they open it. Equally important is to connect your email to the subject line. This keeps you from filling your email with redundancies and wasting someone's time on paragraphs of superfluous information.
Keep it simple. What looks good on your computer may not look so great on someone else's. Try to exclude complicated html or bandwidth draining graphics. Someone shouldn't have to wait for your email to download onto the computer screen before they can read it. The simpler your email, the more likely it will be read and understood by both your recipient and their computer.
DO NOT WRITE IN ALL CAPS. All caps to the eyes is what shouting on a megaphone is to the ears. It's one of the rudest things you can do online and should always be avoided. On the opposite end of the spectrum, try not to write everything in lowercase because it makes you appear lazy. It's easy to avoid these mistakes if you simply exercise proper grammar, punctuation, and spelling in all of your emails.
Know your audience. Writing to a friend is vastly different from writing to a potential employer. Use the appropriate language for each. To make sure you've assigned the right tone to your email, read over it several times. If it sounds off, re-write it and proof read it until it looks ready to send.
Lastly, end your email with a signature. Like the body of your email, it shouldn't be filled with redundancies. The person receiving your email needs your basic title and contact information, not a link to your twitter and facebook account, your three different email addresses, an inspirational quote, and a JPEG of your actual signature. You know you are an offender if your signature extends 4 lines. Put your name, title, and phone number. If the person you email wishes to contact you further, they shouldn't be overwhelmed by options on how to do so.
Writing an email is a basic skill, but there is a professional way to do it. By exercising netiquette, you can ensure a successful, pleasant exchange online.