頭問候其實也的時候是不太需要的. 看情況來說. 結尾的部分其實會比開頭問候來得重要.
How are you?
Hope everything is going well.
Thank you for expressing your (concerns, ideas, suggestions, etc...).
It's good to hear from you.
Your (support, idea, etc.) to us is very important.
Thanks with regards,
Looking forward to hearing from you.
I look forward to hearing from you.
We’re looking forward to meeting with you.
I hope this will answer your questions. If you have any other questions, please don't hesitate to let us know.
如果有些問題沒有辦法馬上回應, 需要上報之後, 才能解答的話:
I will let you know once we have a solution for this problem.
We are terribly sorry about all the hassels(problems), we will work as soon as possible to have it fixed.
We apologize for this (mistake, problem, etc...), we will work out a solution as soon as possible.
Thank you for your support of (company name)!
Thank you for your patience and understanding.
Thank you for your suggestions and support.
It has been a pleasure reading your email. Thank you.
基本上好事可以用"I", 需要道歉或者需要回覆什麼不好的事情問題時, 用"we"比較好.