How can I automatically forward an e-mail and change sender?

[vip11]

I would like to set up an e-mail address that would forward all incomming e-mail and change the sender.
Example: Random person sends mail to an account that I set up:
From: randomperson@randomsite.comTo: aggregator@serviceprovider.comSubject: Test messageHi!This account will then automatically forward it to another adress with itself as a sender:
From: aggregator@serviceprovider.comTo: finalrecipient@somewhere.comSubject: Test messageHi!I am looking for some kind of service that will let me do this, since I do not have a available server to configure. I tried playing around with forward settings in hotmail, gmail, etc. but I cannot make it change the sender address.