There are emails with intentional mistakes; but they tend to be riddled with them — like modern scam texts\emails that have laughable typographical errors and are very clearly a scam yet somehow still work on people that they shouldn't work on.
But this email has a single mistake in it. Just one. It has proper capitalization, proper punctuation. The person who wrote this email clearly knows US English enough for there not to be any obvious spelling mistakes. And seeing that the store ladyparts.ic is labeled as belonging to bigdaddyhurt, I imagine that this fictional person is actually quite literate and that this is not an intentional mistake.
However, I could be wrong. Apologies if I am.