This goodbye letter from a company that is going out of business is directed at their customers and the public.
Dear {Recipient},
I am sorry to inform you that on {date} of this year, {Company Name} is going out of business. Thank you for your loyal patronage over the years, and I hope that your purchases were all to your satisfaction.
As we are closing our doors forever, the remaining merchandise will be going on sale from {date} to {date}. If you would like to put in any more orders before we close, all items are {marked down, shipped for free, etc.}. Please visit our website at {website} for more information.
Sincerely,
{Sender}