The most important rule in office email etiquette is to use the email for work-related correspondence only. It's that simple. If it isn't related to work, you shouldn't be using your work email; that's what personal email accounts are for.

Forwards:

Again, if it's not work-related, don't forward the email to your coworkers, no matter how cute, funny, or dire the email may seem to be. If you believe that you will have considerable bad luck by not forwarding an email to seven friends within seven hours, use your personal email for that purpose. (It may also be wise to find out whether friends or family accept that type of email, too.)

There are a number of hoaxes and false rumors spread through the forwarding of emails, particularly ones asking recipients to boycott certain companies or products. Please, before forwarding these, do your own research to find out if these are true or false claims. There are reputable websites out there that research many of these, and in many cases, you can contact manufacturers or companies themselves to find out if they are based in truth. Please do your research before forwarding false information!

Grammar:

Inter-office emails should be legible to all recipients. Not everyone is a grammar-freak, of course, but please save text or chat speak for personal correspondence. Compose an email using the language you would use to speak to your boss, a fellow employee, or a customer. Write clearly and do your best to use correct spelling and grammar. Use a spellcheck program before sending an email!

Humor:

Humor can be difficult to convey through written words. Tone and inflection are not apparent in an email, and it can be easy to offend when you're trying to be comical. Save humor for speaking if you must share an anecdote or humorous comment. Sarcasm and wit are difficult to express when written; leave that to professional humorists, writers and comedians.

Fonts:

Stick to traditional fonts like Times New Roman, Arial, etc., traditional font colors (black on white background), and please no all-caps. Not only is it hard on the eyes, in the internet-world, it is considered "shouting" and can be taken as an offensive tone. Again, tone and meaning can be hard to convey through a typed correspondence.

Greetings & Salutations:

Don't forget to address the recipient of your email, and close the email with a common salutation, like "Sincerely, your name." Even if you're in a rush, it only takes a second to be polite. Short emails that contain only one sentence or curt language can be mistaken for rudeness or inconsiderateness. Also, don't forget "please" and "thank you," when appropriate.

Giving a little thought and effort toward email etiquette can go a long way in maintaining a good office morale. Just remember to be professional and courteous, and leave personal emailing to your personal email accounts.