Dear Ms. Garrett,
We would like to express our sincere appreciation for your service to us as one of our dearest regular suppliers. Over the years, you have provided the best products with even better customer service. Deliveries are often received earlier than expected, and you are quick to resolve any issues that arise.
We look forward to extending our contract with you for years to come, and hope you will continue to provide such excellent service to us. We could not conduct our business without you! Thank you for a favorable first year in business together, and we look forward to many more to come.