Dear John Smith,
You are kindly invited to a commercial party at (address) at (hour) on (date).
Dress code:business casual.
R.S.V.P
Yours,
Abc Def
Sale Manager
(Date)
括号里的内容按实际情况填写.
百度教育团队【海纳百川团】为您解答,请点击“选为满意答案”按钮,请问能再多点儿句子吗，感觉太少了哈。。。商务信件以简洁为好。客户没有时间跟你拉家常的。这是礼节。