I don't know how to use "enclosed" in English ?

I don't know , please can you explain to me?

Enclosed means to be within a wall or a fence. To have put a wall or fence around something e.g. Enclose a garden with a wall.

To enclose something (a letter) in an envelope, e.g. Please find the drawings enclosed with this letter.

But for an e-mail you would say "attached".