Dear …
We want to take this opportunity to extend our thanks to __(you/name of company)__ for your donation of the __( type of goods donated)__ in our __(name of)__ Fundraising Auction. Once again, it was a tremendous success. Your contribution helped us to raise __($amount)__ , which __(enabled us to reach our goal/exceeded our target of $amount)__. We are grateful for your support.
Over the past __(#)__ of years, we have given our support in helping to raise funds for __(name of organization)__. This commendable organization provides the __(describe what the organization provides)__ for the __(type of cause)__. It was our pleasure to have been able to participate again in this worthy fundraising event.
Thank you again, for your support. It was so greatly appreciated.
Sincerely,