The most common mistakes when writting an email.

Most professionals spend their days sending email after email, making it easy to overlook mistakes or forget common courtesies. However, even these small details can make a big difference.

"A poorly written email can discredit your professional image," says Diane Gottsman, etiquette expert and founder of the Protocol School of Texas. "That's just as important as your business suit, the way you carry yourself. It's part of who you are in business."

While it's easy to send a quick reply from your phone, it's important to take the time to double check every email you send.

Here are 12 common mistakes you should avoid: 

Forgetting to use a greeting or closing

Always open with a greeting when beginning a conversation. Otherwise, your email will come off as terse and demanding, says Judith Kallos, an email etiquette expert. The same goes for including a closing line. "Every single word you speak or type is about forming an impression and building your brand," Kallos says. Leaving out these simple pleasantries won't give off a friendly vibe to potential clients or partners. 

Being too formal

While formality remains crucial to professionalism, if you're emailing a client you call by their first name in person, don't revert to an honorific, such as Mr. or Mrs., in the email, Gottsman advises. Your email opening should always reflect your relationship with that person.

Becoming too informal too quickly

While an email thread can swiftly become short and friendly, starting off too informally — for example, saying "Hey Megan" instead of "Hello Ms. Smith" to a new contact — may seem disrespectful. "It can smack of a lack of professionalism that may cause people to wonder what else you don't realize is important or take seriously," Kallos says. Always start a conversation politely and formally, and follow the other person's lead. Gottsman recommends waiting until they sign off using their first name to use it yourself. 

Saying "to whom it may concern" 

This greeting is the email kiss of death, Gottsman warns. "It shows you haven't done your homework," she says. "It's so easy to find out who you need to talk to if you put in a little effort." Taking the time to include a name will make your email feel more personal and less generic. If you can't find a specific name, try something like "To the consumer affairs department" or "Dear hiring manager."  

Forgetting to change the subject line

Most people forget about the subject line, one of the most important parts of any work email. Every time you begin discussing a new topic, change the subject line of your email thread to make your conversations easy to locate in the future. It's confusing if your exchange about advertising is in an email labeled as sales, Gottsman says.

Hitting "reply all"

Unless what you're saying applies to absolutely everyone, respond only to the sender, Gottsman says. It's annoying to receive one-sentence responses from 40 different people, especially if the topic isn't relevant to what you're working on.

Not paying attention to detail

Small details speak volumes in email, as any stray keystroke can completely change the tone or tell the recipient that you don't care enough to put in more of an effort. Always be sure to spell names correctly and double check for typos. Additionally, never put names in all lowercase or all caps either, says Kallos. It makes it look as though you didn't care enough to properly format their name. 

Including too many personal details

No one wants to read through more than they need to, so keep emails concise and leave out personal details. "Business email etiquette developed because people want to hear about just business, not your cousin or grandmother," Kallos says. Save your personal updates for another time. 

Not monitoring your tone

"Since people can't hear our tone of voice, we have to remember that all they have is the written word," Gottsman says. "The writer needs to make sure that they are writing for the reader to understand." This makes phrasing and formatting extremely important to clearly getting your point across. Always take the time to find the exact word that conveys what you mean, and only bold something if you're ready to stand by it, Kallos says. "If you type it, you better mean it," she adds. People will take things the wrong way, so avoid even giving them the chance to.

Asking questions that have already been answered

Asking unnecessary questions not only wastes the other person's time, it shows that you didn't pay attention to what they said the first time around. To avoid this, Kallos suggests answering emails point by point. "People love it because they know you've taken the time to address each and every one of their concerns," she says.

Saying something over email that should be done face-to-face

Some things, such as offering criticism, can't be said over email without creating a misunderstanding. Learn to recognize these situations, and pick up the phone or walk over instead of sending an email. "On email you don't have the eye contact or the body language, so there's times you've got to add that personal touch," Kallos says.

Using emojis or abbreviations

Emojis and abbreviations are generally unprofessional in business emails, Gottsman says. Leave out the smileyfaces and LOLs, and be sure to spell out words like "appointment" instead of writing "appt" if you're writing to your boss or a client, which shows that you're taking adequate time to respond to their email instead of using quick shortcuts.