We've all sent an e-mail that was less than professional at one time or another.

Editor’s Note: Brenna Ehrlich and Andrea Bartz are the sarcastic brains behind the blog and book “Stuff Hipsters Hate.” Got a question about etiquette in the digital world? Contact them at netiquette@cnn.com.

Story highlights

Our Netiquette columnists cite common e-mail mistakes you shouldn't make

Don't mark all your e-mails as urgent

Be clear about your message in the subject line so it won't get overlooked

CNN  — 

Unless you are a shiftless layabout, you’re probably going to have to e-mail someone more important than you during the course of your lifetime: a boss, a professor, President Barack Obama (if you’re a confused elderly person and you think those campaign e-mails he and Beyoncé are always sending are actually addressed to you).

And, when that glorious time comes, you will probably mess it up in one way or another, thereby demolishing that relationship along with your pride. Why? Well, because it’s just too easy to dash off digital communication these days. There are so many case-in-points to support this assertion that we’re just going to leave this picture of a kitten so you don’t lose all your faith in humanity right here and now.

Blame it on the slow degradation of the English language, blame it on the anonymity of the Web and the trollishness that it breeds, blame it on the rise of the smartphone.

We’ve all sent an e-mail that was less than professional at one time or another, and we’ll probably send more as the years pass and the government starts replacing our brains with iPhones so that we can send messages directly from our thoughts (can you say dystopia?).

Still, a little awareness can go a long way toward curtailing future follies. We’ve compiled a list of common e-mail mistakes so you can avoid any massive fallouts with your boss/contact/Obama.

As for the future of your brainstem, you’re on your own, kid. We’re all on our own.

Don’t blank when it comes to the subject line.

So you have an awesome new marketing idea for your company that involves re-enacting that David Blaine Electrified stunt, with your CEO as the human torch. You have all the necessary skills to pull it off, having read a book about Tesla coils once. In a fit of urgency and illumination, you dash off an e-mail to the CEO outlining your amazing and totally-safe-and-not-dangerous-at-all idea. Unfortunately, you fail to include a descriptive subject line in your missive, perhaps something along the lines of “Innovative Marketing Idea That Is Totally Safe and Won’t Kill You I Promise.”

We know you’re so super busy that half of your lunch is now embedded in the grooves of your keyboard, but is it really that hard to eke out another word or two before sending that gem into the abyss? If you don’t state your purpose right off the bat, it’s likely that your boss/contact/other important person will just ignore your subject-less e-mail wholesale or assume that it’s spam and banish it to the digital dustbin.

And then you’ll have to live out your Tesla fantasy all on your own – and you’ve already killed two of your wife’s cats, now, haven’t you?

Everything is not urgent

Although the fact that someone stole your “Hang In There, Baby” poster (again) may be an emergency to you, it does not necessitate the “High Priority” designation you’ve slapped on there. Especially if you’re sending out an office-wide e-mail that’s going to bosses in addition to subordinates.

If the fact that you had a “Hang In There, Baby” poster didn’t already make you appear unstable in the eyes of your co-workers, caterwauling (see what we did there?) about its disappearance in such a manner definitely will. Yup, you can say “goodbye” to that promotion and “hello” to even more depressing motivational reading materials.

A boss by any other name is not your boss

Don’t spell your boss’/contact’s/lord and savior’s name wrong. It makes you look dumb, and no one listens to dumb people.

Don’t send out a blanket ask

(Based on true events) So you just moved to a new city, and you’re looking for a gig – but you don’t know anyone at all near your new digs, aside from all the local bartenders and the nice man at the bodega who sells you sandwiches at 2 a.m. after you’ve finished visiting all the local bartenders. Conscious of your plight, a friend helpfully provides you with a list of local contacts and says heartily, “Network at will!” as he claps you on the back, fat cigar and whiskey tumbler in hand (as successful people are wont to do).

With dreams of fat cigars and whiskey tumblers swimming in your head – a definite step up from the rail liquor and bodega sandwiches you’ve been living off of for the past few months – you send out a mass e-mail to all of your new contacts reading: “Hello! I’m looking for a job! Here is my résumé.” You’ve savvy, so you make sure to BCC the entire contact list. Like a contented cat, you lie back and wait for the responses to pour in like so much job cream.

Sadly, friend, they never will. Why? When reaching out to new contacts, it’s extremely tacky to send out a mass e-mail. You’re asking these people to help you out. The least you can do is 1) address an e-mail to each person by name and 2) tell him/her who forked over his/her information in the first place. That way, said person can ask your friend whether you’re a raving incompetent all the time or only on special occasions.

Avoid the wrath of HR

Have an awesome CreepShot to share with your boss? Don’t. Just don’t.

Also, you should probably seek counseling. Or a life.