Dear XXX,As…(表示相关).From now on, the ways that you offer are quite good; however, Ihave some better suggestions for you. Firstly, it would be greatly appreciatedif you could…., because…; Moreover, 原因,so it is advisable for you to···I hope that you will find thesesuggestions helpful and I would be readyto discuss this matter with you tofurther details. I am looking forward toyour reply. Sincerely yours,
Li Ming
2. 投诉信
Dear XXX.l am•who(定语从句解释遇到的问题）。1would be grateful if you could doanything necessary to solve the problemfacing me.具体事由.To resolve the problem, it isadvisable for you to方案(+原因）.I hope that my problem will get yourkind consideration.