【答案解析】[参考范文]
Dear Jack,
I am writing to give my advice on your addiction to online chatting. I am so worried about you since you have spent too much time on online chatting. It causes you to neglect your work, your relatives and friends and many other important things in life. Besides, your addiction to chatting online has disrupted your regular life pattern, which is further harmful to your health.
It"s time for you to strike a balance. Here are my suggestions. First, the amount of time spent on Internet chatting should be considerably reduced. Second, you should stay connected to the offline world and contact with your families more often.
I sincerely hope that my suggestions can do you a favor.
Yours sincerely,
Li Ming
[解析] 本题要求写一封邮件，实质是建议信。建议信一般是提出建议或忠告。写作可以按照如下步骤进行：(1)开头阐明写作目的；(2)委婉提出建议；(3)希望建议被采纳。写作时注意语气要恳切、诚挚，建议内容应具体，便于实施。