Translation:I already put that envelope in the mailbox.
And how does it change the emphasis of the sentence if it's not in front of the verb?
What would be the difference between this and "I put that envelope in another mailbox"?
You could write that as あのふうとうはほかのポストに入れました Instead of もうポスト it would be ほかのポスト
"That envelope has already be placed in the mailbox" was not accepted. Shouldn't it be?