When a mail is send to any person by you than it contains few parts which is required to fill by you before sending. They are Sender address i.e your address Receiver address i.e. the address to whom the mail will be delivered.Message body,message header..etc..
When you
sending mail using any stander mail client or interface like Gmail,yahoo
etc than you are not asked for the the Sender address i.e your own
email address.By default your email ID is sended to the mail server as a
sender address.But We can change that sender address by changing that
Address.
