Subject: (Mention the purpose of writing the letter)
Dear Smith (Sir or Madam),
I am writing to request you if a silent auction gift card can be donated for ______(Mention the name of group). As you already know that it is a nonprofit organization and supports ________(Mention the cause that it supports).
A silent auction is being planned for our meeting on ___(mention the date) and would be great if your spa was also included. When I was given the responsibility of finding donors, your name came to my mind immediately. I will call next week.
Feel free to drop me a mail at _____(email address). Thanking you.