1.) using a very short period of time. For sending data to the recipient.2.) can go back, come and see the information received from the sender, the email system to record data. For the sake of the historical information
1) Using a very short period of time. For data transmission to the receiver 2) to return to the information received from the sender's email system to record data. In order to get the information back.
1) using a short. For data transmission to the receiver 2) can look back at the data received from the sender e-mail system to save the information. For the sake of finding information backward.