​EXECUTIVE SUMMARY: Focus on radical transparency and timeline reallocation to prevent relationship fracture. ​THE RESPONSE: "Dear [Name], I am writing to provide an update on [Project]. Due to unforeseen technical hurdles, we are adjusting the delivery timeline to [New Date]. Maintaining our quality standard is our priority. I have expedited the remaining phases and will provide a daily status report until completion. Thank you for your continued partnership." ​STRATEGY NOTE: By providing a specific new date and a daily update plan, you replace uncertainty with reliable control.