In general, I don't pay any attention to bad spelling/grammar/whatever in anything sent to me by friends. Use the wrong form of "their/they're/there" in a personal email to me? I'll read past it and continue on.
Text me something that has words like "teh" or phrases like "Do you wand to got?" and I'll ignore them and try to read between the lines.
But send me a business message with a massive typo in it and, yes, I'm going to notice. After all, to me, there's a hierarchy to communications, and I've always believed that you have to pay more attention to business communications than you do to casual messages.
Well, I'm not sure whether the author in question would agree, since this was the (complete) message he sent earlier this week in response to an explanation about one of our procedures:
"This makes complete sentence."
And, you know, that does make a complete sentence. I'm just not sure it makes... well... sense.