Is earning by sending mails true?

I'm not sure if this is true because I signed up for Peoplestring.com and they had a mailbox program that allows you to earn money just by "walking up to your mailbox". It's been two months already and I still haven't recieved mail from hem. However, it's not like they created the whole getting paid for mail, and stuff, so I THINK it's true. It had to be based on someone else's ideas.

Dear I am interested so I am sending you freind request so accept it and give me link well how much I will get per sending email and what is payout and method and any good reason that you feel that it is legit well share your experince here dear

if you want to sell product online then you can make money by email. in that case you will have to send the link of your website or product where you want to sell. if email user would like to buy your product this way you can make money. apart from this i have heard that there are some persons on odesk.com website where they hire people to send email. that is also a way to make money.