Disregarding the entire content of his email while simultaneously nitpicking his email etiquette is never going to come across as "friendly". As its written, y

Disregarding the entire content of his email while simultaneously nitpicking his email etiquette is never going to come across as "friendly". As its written, you just seem like you're dismissive and passive aggressive. If you had actually responded to the email and then added an aside about his email subject it would have come across much differently.