When an e-mail message cannot get to its recipient for some reason, it is returned or bounced to the sender, with an error message informing the user that it was not sent. This is also known as "bouncing back." You may hear someone say, "I tried to send you an e-mail message but it got bounced back." If this happens to you, check the e-mail address and contact tech support at your ISP.
NetLingo Classification: Online Jargon