無事勿擾既英文

我會咁講:

1. I'm currently busy, please do not email unless it is for urgent matters.

好少西方國家會用disturb呢隻字, 因為被人感覺較rude, 比較常用既都係一些簡單直接如, sorry i'm currently busy or sorry i'm concentrating at the moment等等. either one既講法較為圓滑一點

您好，我推薦您一個非常不錯的英語學習網站，里面有很多非常不錯的學習資源，您能從中得到不少幫助：

http://www.hkenglishstudy.info

祝您好運!

(1)I am busy.Please don't send me messenger.Unless you are really very important matter tell me.
(2)Please don't disturb,supposing it is really important

I am currently very busy. Please do not email me except for emergency case.
Please do not disturb except for important or urgent cases.

It is better ( more friendly) to use do not instead of Don't, which is normally used for command case.

I am very busy right now. Please don't disturb me if there is nothing particularly important.