It should not come as a surprise that the communication style of the general public has changed drastically in the last decade or so. Cell phones, instant messaging, and text messages are so common that I put it past you to find anybody under 65 who is completely unaware how to use any of the aforementioned technology, or at least how it works. While this increase in instant communication means that connecting with others is faster and easier than ever it seems to come at a relatively high cost.
What is that cost? Spelling and grammar have gone out the window in lieu of more conveniently sending 'c u l8ter' to save a few keystrokes. Hopefully nothing of this sort makes its way into professional communications, but it seems as though this lazy approach has made some headway into the professional world as well.
While working for a staffing firm it was required that salespeople copied the recruiter on communications sent to the customer. This was a great way to keep the recruiter in the loop on where his or her candidate was in the process, but gave me more gray hair than I could count. It was terrifyingly obvious that the senior salespeople in my office wouldn't stand a chance at passing a high school level English course! Each time an email was sent with spelling errors, poor grammar, or schizophrenic punctuation I cringed. I kept thinking to myself how incompetent our customers must think my company is if the salespeople can't even accurately proofread an email.
Everybody knows that first impressions are important, and making a bad one is hard to get over. If that is the case, why would you ever send a communication out that was anything less than perfect? It was beyond me how it could be allowed. I kept making mentions to management that perhaps a grammar refresher course should be taught, but my requests fell on deaf ears. I checked a little further into the problem only to discover that there were 15 typos on the applications we sent to all of our potential hires (in my defense not the same one I used to apply). I was absolutely mortified!
I did a very informal study while working there to see how this poor communication affected success. Although I cannot claim that communication was the sole reason for this, the salespeople with proper spelling and grammar in their emails booked almost double the hires as their sloppier counterparts! I won't claim to be perfect myself, and know that on occasion a typo or grammar error is acceptable. However, I think anybody in the position to communicate with customers should take professional communication refresher courses every year or two. Outside of maintaining proper grammar and spelling, documentation styles and formats evolve over time so any good salesperson should want to stay current.
I am normally quite a forgiving person myself, but have to admit that if I disqualify a candidate for having too many typos or errors on a resume, it will be hard to justify working with a vendor that doesn't take the time to proof an email.