A new problem of our super tech-savvy world is email communication. When do we send them? How often? And, most worrisome of all, what do we say? Studies show that the average employee spends about 25 percent of each workday simply sorting through, responding to, and creating their email messages. Yet, despite all the time we spend writing electronic notes, very few people actually know how to send good emails.

In order to execute emailing successfully, you have to master grammar and punctuation--as well as know when to switch from being overly formal to carrying more casual conversation on the web. In her book, The Essentials of Business Etiquette, career coach Barbara Pachter reveals some email etiquette tips to keep you from looking unprofessional.

1. Overly informal greetings

"Hey" or "yo," for instance, is much too casual for the workplace. When in doubt, shoot for more formal than less, because the email recipient can always adjust the tone as he or she sees fit. Pachter says, "Hey is a very informal salutation, and generally it should not be used in the workplace. Use Hi and Hello instead."

2. Inappropriate jokes

It's too easy for humor to get lost in translation via email. Many people forget that body language, facial expressions, and intonation color so much of what we say. When we strip faces, or a human touch, away from our messages, what you're trying to say may not come across--and instead come off as unprofessional. In regards to humor, Pachter advises, "When in doubt, leave it out."

3. Disrespect of other cultures

Depending on where we grew up, we have very different ways of talking and typing. Be mindful of those cultural differences when conjuring up your responses. As a general rule, Pachter says that high-context cultures (Japanese, Arab, or Chinese, for instance) may want to get to know you better before doing business together.

4. Spelling and grammar mistakes

It takes maybe 30 extra seconds to do a quick scan over your email message before sending it. Your mistakes, no matter how small, will be noted by whomever is on the other end. And, according to Pachter, "you may be judged for making them."

5. Sending incomplete messages

There is nothing worse than sending an incomplete email, or to someone you didn't intend to. So, the best solution is to simply strip away that option. Add the recipient's email address right at the end in order to ensure that you've had time to compose a stellar email before sending into the pixelated abyss.