"Their's ????? I agree with Pappy."
I sure hope you counted all FOUR errors and not just this one that you have cited.
It's appalling how badly formed many emails and postings have become - not just on Agoracom but in almost every other forum and social website.
It's a symptom of poor education, lack of caring, lack of attention to detail or a mixture of all three.
The effect is lost productivity in having to re-read the text to be sure one has correctly understood it.
Occasional typos will happen. Consistent errors in spelling and grammar are a regrettable sign of the times. If someone can't get just a few lines correct, how attentive are they to business and legal documents, both writing and reading them?