No wait, that doesn't make any sense. Is it indeed encrypted before it is send and is it encrypted by the receiving computer? Or does the first Tor node encrypt it and the last Tor network decrypt it????
The first Tor node is you.... You encrypt the packets and send them on their way. The intermediate Tor routers do not know either the origin nor the contents of the packets. The final Tor router, (or the Tor computer if both of you are running Tor because I believe that the Tor computers become part of the network) _has_ to decrypt the packet in order that the receiving computer can understand the request. There is no telling how many hops the unencrypted packets go through and therefore no telling how many people can see the data. But, there is also no telling where the packets originated since that information is only held by the first router in the chain.

So, in order to remain absolutely anonymous you must not have any identifying information in that packets you send to non Tor boxes because the final router may be several untrusted hops away from the target.