We thank you for your order and hope we shall fill it to your satisfaction.
Please investigate the delay at once.
The participial ending is merely a sort of habit. A letter used to be considered lacking in ease if it ended with an emphatic sentence or ended with something that had really to do with the subject of the letter.
It might be well in concluding a letter, as in a personal leavetaking, to "Stand not on the order of your going." Good-byes should be short.
CHAPTER V
PERSONAL LETTERS—SOCIAL AND FRIENDLY
Invitations and Acknowledgments
General Directions