Postfix: Enable only high ciphers

I try to enable only secure high ciphers.
With those

smtpd_tls_auth_only = yes
smtpd_tls_mandatory_ciphers = high
smtpd_tls_protocols = SSLv3, TLSv1, !SSLv2
smtpd_tls_mandatory_exclude_ciphers = aNULL

Disable sslv2 but nessus say weak and medium ciphers
still enabled,how to enable only high?
Thanks