text: how can  know whether someone's email id has expired or not when that id doesnt respond? can i know about a person by his id??? there is a program called yahoo intai, search it with the help of google. it reveals hidden yahoo messenger users if they r trying to hide. there is also a validation option that it has got, that validates whether the messenger exists or not. the emails will be bounced back to u if they r not able to reach the expired id.