Postfix & Address Rewriting Problem!

Dear People,

This question might be asked already but I could not find it.

I have a problem with postfix Address Rewriting option. The problem is that postfix does not rewrite address for users has no domain and "return-path" is invalid address. For example a sent message has a header like this :

When I change the value "append_at_myorigin" to "yes", it seems to be OK for sending e-mails but no email can be received then.

Any idea?

Regards,