英语书信我开头有两个格式:

To whom who may concern, (老式)

或:

Dear sirs or madam,(新式)

Your Ref: Enrollment application (对方档案纪录)

I am so sorry to inform you that due to the changing of situation. I won't be able to come and study in your school anymore. Therefore, please remove my name from your application list. My most sincere apologise for any inconveience it may have caused. With regards.

Yours Truly,

XXX

以上是最标准的英文信，不单止有礼貌，而且解释详尽，希望会获采纳，谢谢你。