I hope this letter finds you and your family well. [Blah blah blah pleasantries]
I find it deeply unfortunate that we are not better acquainted, especially now that I am paying court your sister. I doubt I need describe Miss Lestrange's many merits to her own brother, though I can assure you that I consider your sister to be the finest of ladies.
Therefore I should like to propose we meet at the club next week, at your convenience, and remedy this over a drink.