Those who are using internet all of them have email account. But there may be someone who have no email or just lazy to enter into email but need to send a note to his or her friend. Here is light site( light means very quick loading) that is giving you this opportunity. You can also send email anonymously.
For this you have to enter into this site. Then fill the form properly , choose one of the two options( i choose without any key) and send. So mail will be sent to the email you wrote.
You can also use this for sending any small note in your own mail box(what i usually do to save some information as a draft) easily just making a tab, without waiting for loading your email account or writing email ID and password.
In this case, as a sender email@example.com will be recognized to receiver.