Hello guys! As usual I need your help, I'm searching for an application which I don't know the name of!

What I know is that it sends messages from one mobile phone to another, (the message maybe in the form of an email) but, here's the tricky part, the recipient doesn't see the sender's number! Instead, the message will show their own number. Kind of confusing I know, but I really need someone's help! Perhaps anyone here uses this kind of application?

Post your replies here or you can pm me. If someone knows a name of such application, or a link to some information, I'd really appreciate it!!!

~Zarnaz.