Or the ending:
"I have the honour to be, Sir, your obedient servant"
but I prefer:
The Duke of Wellington is said to have once ended a letter "Your most humble and obedient servant (which you know damned well I am not).
But wouldn't be wonderful today not - using such a formula as some kind of ***-take - but to petty officials and MPs
"You have the honour to be, Sir, my most humble and obedient servant."