You don’t respond
You’re sitting in a team meeting at work and your colleague asks you a question you don’t really feel like answering. As much as you’d like to pretend you don’t hear her, you have to say something. The same courtesy should hold true for email, but research shows otherwise: An average email user responds to less than 25 percent of email messages received from their contacts. So basically, you're ignoring about three out of four emails. You get busy. We all do. But if someone you know well emails you a question, clearly they want to know something, and replying is the right thing to do. And good communication is an important job skill. An appropriate response would be even better: When your coworker asks for your quarterly report or your mother-in-law wants to know what time to come for dinner, don’t shoot back “OK.” You know you didn’t read her email, but now she does, too.
You respond to an email, but barely
Researchers at the Yahoo Lab examined more than 2 million users and 16 billion emails over several months, and found that the most common length of an email reply is five words. Just five, lonely little words. Granted, there is something to be said about brevity, and perhaps in some cases, few words are needed. But “have a nice day” or “thanks for your email” is already four words—just saying.
You leave the subject line blank
Or you fill it with "Hey" or "FYI," which completely defeats the purpose of the subject line. Give your recipients a hint—about 70 percent of them think it’s unacceptable when you don't, according to one survey. And considering more than half of emails are read on a smart phone, make sure that "hint" is clear and concise, so the important words don’t get cut off the small screen.
You cry wolf
In email speak, that’s marking your message "urgent" when really, it's not so much. Save that red flag for real problems; otherwise, it loses its attention-seeking luster.
You type in color
You also think Times New Roman is so yesterday, and more font sizes are better than one. Far from anyone to stifle your creativity, but perhaps save it for another medium. In a survey of more than 1,200 people conducted by BuzzStream and Fractl, two content marketing agencies, over 60 percent of respondents found irregular typefaces (like Comic Sans or Courier New) and different font colors and sizes objectionable. You know what irks people even more? Spelling and grammatical errors, with nearly 80 percent saying those two are the most unacceptable offenses. However, it's fine to ignore these classic grammar rules.
YOU LOVE ALL CAPS!!!!!
That’s nice, except you’re screaming from the screen. If you want to cap-lock a “CONGRATULATIONS” or “GOOD LUCK,” that’s one thing. But most everything else that needs a little extra attention can be sufficiently emphasized with a bold or italic. And go easy on the punctuation, as well: One exclamation point can convey excitement, 17 is over the top. “People sometimes get carried away...but the result can appear too emotional or immature,” says Barbara Pachter in her book The Essentials of Business Etiquette.
Your signature is a mile long
It’s a way to introduce yourself to the recipient, so it stands to reason to include your name and title, company you work for, contact phone number and email, and website if you have one. What ranks least important in a signature: social network links, chat handles and disclaimers, according to one survey. And what those who know you well, and those who don’t, will likely find most annoying: having to read your favorite quote every single time they get an email from you.
You ‘reply all,' all the time
Would you like to be notified 15 different times about 15 different messages, 14 of which don’t apply to you? Unless everyone in that group email really needs to see what you say, reply only to the sender. And along the same unnecessary-chain line, say you and your friend have written back and forth, and back and forth, and back and back and forth and forth, about taking a cruise together. Now you want to invite your sister. Spare her the torture of trying to follow the forwarded thread; instead, summarize or highlight the important parts.
You have an in-office auto-response
That’s the kind that goes something like this: “Thank you for your email. I get an overwhelming amount of messages, but will do my best respond as soon as I can.” You may as well say: I'm more busy and important than you are. Even if your intentions are good, by warning people your response may be slow, it can come off as arrogant or condescending. "An automatic email should only be used if you’re out of the office on vacation or unable to respond to email because you’re on a safari or something,” Cherie Kerr, author of The Bliss or “Diss” Connection: e-mail Etiquette for the Business Professional, tells Forbes.com. “A robo-response can distance someone and who wants that?”