I find it fairly common for people that do not have US English as their first language to not use punctuation the way that I was taught in school. I do that too when I think the punctuation is wrong for what I'm conveying (especially . or , inside quotes, when quotes are a command). Non-native people commonly use quotation marks that I don't know how to produce with my keyboard, put $ after the number, etc. A space before a question mark is not unheard of.

The somewhat read flag is "kindly" (likely Indian?) with "Marc" (likely not Indian) but it's common for people with a name that's difficult for Americans to understand/spell to use an Americanized name.

Using an email address that doesn't match up with the company's well known domain name is a real problem. Suggesting payroll comes by something other than check or direct deposit is a red flag. Luckily, requesting money via wire transfer tipped this person off before things got real bad.

I don't see how professionalism is tied to English proficiency. I've spent my whole career with ESL people (me included) and it doesn't really make sense to me.

I'm a non native, difference of "it's" and "its" is easy. Commas (and other characters like ; : ) are far more difficult.

As a non native speaker, I find it wild you think it's vs its is harder than punctuation. If somebody can't tell its from it's then they don't know what a verb is, which seems like a much more basic concept than punctuation to me.