You can use any antenna in the receiver, but legal rules usually impose some restrictions in the transmitter antenna. This is to avoid a high level in the transmitted signal.
Think that 433 MHz is used mainly for remote control apps: The same frequency can be shared by several users, since the transmissions are NOT frequent. Thanks to the use of different codes, collissions only imply that your garage door does not open. Although not frequent, codes might match and your door be open by the neighbour.
Statistical studies (and political reasons)deliver a set of reasonable rules: Max. transmitted power, Max. antenna directivity, etc.

The use of this band for continuous data transmission is not advisable.

Alfredo.