What impression do you create when you send e-mails? Every single correspondence you make directly influences how people perceive you and your company. From the content to the timeliness or response , everything you do impacts how others think of you and the company you work for.

Here is my take on the 5 E-mail Commandments:

E – Email only the people to whom the message actually pertains. Just like how people do not like to receive e-mails that were not intended for them specifically, people also do not like others to receive information that should be proprietary.
M – Make a point of responding promptly. Even if you cannot answer the questions immediately, the courtesy of sending an e-mail that says “I am looking into it and will get back to you as soon as possible.” will ease recipients mind knowing that you received their request, put you at the top of their mind, and it will speak volumes of your professionality. If you respond within 24 hours to a request you will already be ahead of 75% of your competition.
A – Always use spell-check (and grammer check if possible) before sending a message. Most e-mail programs have an auto-spell-check feature. Look for it and turn it on! Nothing says unprofessional more than misspelled words.
I – Include your telephone number in your messages. Most e-mail programs have an auto-signature or footer function. Avoid inserting a graphic of your company’s logo. You may think it looks cool, but it is just a superfluous graphic that your intended receiver needs to download and store for every single e-mail.
L – Learn the difference between business e-mails and personal ones. The only thing that I find more annoying than spam, is junk mail forwarded by business constituents. Think before forwarding.

Other things to think about:

Use the SUBJECT line correctly, people use these to sort through their in-box. Make it short and relevant and try to remove RE: and FWD: they just get in the way of the message. Oh yeah, and do not type the entire message in the subject line. That is just annoying.

Brush up on your grammar. Pick up The Elements of Style or The Chicago Manual of Style.

Personalize all e-mails. It only takes a second to type Dear Mr. ____ and it shows that you respect your recipient, and because of it they will immediately fell more connected to the letter than they would without it.

Make the document look sharp. Avoid too many typeface, color, and sizes. The most professional letters use one font family (usually Times) at one size (usually 12pt) if you need something to stand out use bold, italics or all-caps, but do this sparingly.

Humanize your correspondence. An attachment without an explanation or e-mails with just 5 words like “I NEED THIS NOW” seem cold and bossy, even rude. Adding something simple like “Let me know if you have any questions.” or “Do not hesitate to ask.” lets them know that they are dealing with a human and will increase their desire to work with you in the future.

Keep your messages as concise as possible. This is business and people have limited time. If you get a reputation for writing run on letters people will start to avoid them.

Emoticons are fun and cute when IM’ing your friends and writing personal letters, but their is no place for them in the business world. Clients want to work with a professional who understands their business not with someone who is cute. Can’t you be both? Professional and Cute? Do I really need to answer that?