Note: Upon her indictment on federal money laundering charges and her arrest February 8, 2022, Inc. dismissed Heather Morgan as a contributing columnist. As is our practice, we do not unpublish editorial content, and rather have added this note for full transparency.

One of the most common mistakes in business and sales writing is applying a formal tone to everything you produce.

A colleague of mine recently griped about this, explaining the writing style she learned in business school had no place in today's world, which runs on casual conversations that take place in apps and barely adhere to basic grammar.

Not that we should throw the rule book out the window when it comes to all business writing. In fact, there are plenty of useful lessons we can apply to sales emails, so long as we understand that certain things have changed since the rules were written. For example, opening a cold email conversation with "Dear Sir or Madam" reeks of a bygone era most of us no longer relate to. Including complex words just because you can is equally off-putting for your email's recipients.

Taking inspiration from my colleague, I found several "dos and don'ts" for business writing that match our pace and style when it comes to sending sales emails. Here are some of my favorites:

Three grammar rules to follow when writing sales emails:

1. Using the second person. The point of sales emails is to persuade and even disarm potential customers. You can't do this when you're building a stiff wall between you and the recipient by using only the third person. "Many companies improved their ROI within two months using (Product)" is impossible to relate to because "many companies" is an abstract subject. Instead, give your emails the energy boost they need by bringing the recipient into the conversation: "You can increase your ROI in as little as two months when you use our product."

2. Using active voice. Active voice can mean the difference between a sentence the reader relates to and one obscured in a cloud of outdated writing techniques. For example, instead of "The applicant tracking software is used by many Fortune 500 companies," write, "We help Verizon, IBM, and Chrysler screen new candidates through our applicant-tracking software." Not only is active voice more concise, it gets the point across in as direct a way as possible. Since you have limited space in an email, this is a highly effective way to convey your enthusiasm and your pitch in one sweep, and it's more persuasive.

3. Simplifying sentences. A good rule of thumb: the longer the sentence, the longer it will take the recipient to understand the message--that is, if they even read the whole sentence. If you look back at business correspondences from many decades ago, sentence length wasn't such an issue. However, they were sending letters instead of using Slack and email. To keep up with the times, opt for shorter, punchier sentences that help to slow the reader's pace down. Contractions are also useful here, as are counting the number of commas you have.

Avoid these three things at all costs:

1. Showing off with big words. You shouldn't need a dictionary or thesaurus to write a sales email. Stick to the simplest words possible: Use "hard" instead of "complicated," or "easy" instead of "rudimentary." However tempted you may be to show off a word you just learned, save it for Scrabble and give your potential customers the plain English version.

2. Cramming in pleasantries. Just as "Dear Sir or Madam" would be out of place in an email these days, pleasantries like, "Sorry to bother you" or "I hope this email finds you well" do the opposite of what the sender intends -- they alienate the recipient. Why, after all, would you email someone if you didn't want to bother them in the first place? Skip these pointless one-liners and treat the recipient like an acquaintance from the start.

3. Relying on jargon. Believe it or not, jargon is actually encouraged in some MBA programs. In the real world, however, it ruins emails and confuses people more often than not. It also makes your prospects feel like outsiders, which won't help you set a comfortable, casual tone. Remember, if your potential customer wouldn't use the word with their peers, don't you use it in your email.

My colleague likes to point out that once she left business school, she had to unlearn many things she learned in school to get more email responses and better connections. Of course, it's never too late to start over, but if you can keep these simple tips in mind, you've discovered a handy shortcut to writing relevant business copy for today's sales emails.

What are your favorite business writing tips? Please share them in the comments below.