有甚麼分別? thanks

sent : 過去式
have sent: 現在完成式
had sent: 過去完成式

我將份draft sent左去你e mail : I sent the dratt to you by e-mail..

我(剛剛)已經將份draft sent左去你e mail : I have just sent the draft to you by e-mail.

我(昨天)已經將份draft sent左去你e mail : I had already sent the draft to you by e-mail yesterday.

sent 是 past tense
have sent 是 present perfect tense
had send 是 past perfect tense.
應該用have sent