Would you please wait this letter to see with the postages?
Do you want to sent this letter by ordinary or registered mail?
By ordinary airmail please.
Anything valuable in it?
A post order for four hundred dollars.
In that case, you'd better have it registered.
Will I be informed that my friend gets the letter?
Yes. When your friend gets it, he'll sent the receipt which you send it by mail. then you can be sure he's received.