Spam gets no REJECT

[francwalter at gmx.net]

Hello,

I have on my Ubuntu 12.04 LTS server a postfix 2.9.3-2 MTA with AMaViS 2.6.5 and Spamassassin 3.3.2.
I set in my 50-user setting file for amavis:

$sa_tag2_level_deflt = 5
$sa_kill_level_deflt = 6.13
$sa_dsn_cutoff_level = 100 (only to test, normally 10)

In my blacklist.cf of spamassassin config I set a special E-Mail-address to 11.11 score, so each mail from this address gets +11.11 on its score.

But I never get a message from the Mailer Daemon of this spam-test-address (it is a gmx.net address, by the way) that this mail got rejected by my server.
I find the mail in the quarantine folder (/var/lib/amavis/virusmails), but there is never a message from the Mailer Daemon.

I thought if the score is higher than $sa_kill_level_deflt (6.13 in my case) than it is rejected with a notice, only if the score is higher than $sa_dsn_cutoff_level (100 here) the mail is just dropped, without notice, no message then from the Mailer Daemon of the transfering MTA (gmx in this case).

What do I need to do, that postfix gives a appropriate REJECT to a spam mail?
What could I have overseen?
Is there maybe a postfix setting which touches this behaviour?

Thank you for hints,

frank