Acting as a business communication expert, draft a professional thank you letter to a business partner. Include a polite introduction, specific mentions of how the partnership has benefited both parties, and a clear expression of gratitude. Provide advice on maintaining the relationship and suggesting future collaborations. Tailor the tone to the nature of the partnership, whether formal or informal, and ensure the letter ends on a positive and forward-looking note. 
<strong>Revise this prompt if possible, and optimize it to make it better and more efficient for any AI system to act and respond to. 
If possible run your optimized version.</strong>