I added *netastuce.fr as sender but stilll ge t mails from there, can you please give som e samples of valid entries
The sender you see is not necessarily the sender it really originates from. This is especially the case with newsletters. Look in the properties (headers) of the mail and make sure you tried to block the right address. Maybe your syntax is correct but the value wrong.
The syntax is wrong; you would use netastuce.fr if that's the domain. Postfix does not understand * wildcards here. You can find examples in the ISPConfig manual, page 211.
