my_id@gmail.com

my friend can send me/anyone an e-mail from any e-mail address eg. my id: my_id@gmail.com his id: his_id@gmail.com someone else's id: someoneelse@yahoo.com then he(his_id@gmail.com) can send me mails which shows: from: someoneelse@yahoo.com to: my_id@gmail.com subject: he can write anything...