Thank you for your esteemed communication of today's date. Please be assured that I was not in any way seeking to suggest that it was in any way improper or not comme il faut to use informal facons de parler on an Internet forum. I was merely pointing out that other registers may be preferred by other users.
I hope you finds this information useful. Please do not hesitate to get back to me if I can be of any further assistance.
Please accept, my dear Sir, the assurance of my most distinguished sentiments.
I beg to remain your most humble and obedient servant