diff -Nur -x '*.orig' -x '*.rej' qpsmtpd-0.96/lib/Qpsmtpd/Plugin.pm mezzanine_patched_qpsmtpd-0.96/lib/Qpsmtpd/Plugin.pm
--- qpsmtpd-0.96/lib/Qpsmtpd/Plugin.pm	2016-02-16 23:52:02.000000000 +0100
+++ mezzanine_patched_qpsmtpd-0.96/lib/Qpsmtpd/Plugin.pm	2016-04-15 17:08:29.174840108 +0200
@@ -10,7 +10,7 @@
 our @hooks = qw(
   logging config user_config post-fork pre-connection connect ehlo_parse ehlo
   helo_parse helo auth_parse auth auth-plain auth-login auth-cram-md5
-  rcpt_parse rcpt_pre rcpt mail_parse mail mail_pre
+  valid_auth set_hooks rcpt_parse rcpt_pre rcpt mail_parse mail mail_pre
   data data_headers_end data_post_headers data_post queue_pre queue queue_post vrfy noop
   quit reset_transaction disconnect post-connection
   unrecognized_command deny ok received_line help
diff -Nur -x '*.orig' -x '*.rej' qpsmtpd-0.96/lib/Qpsmtpd/SMTP.pm mezzanine_patched_qpsmtpd-0.96/lib/Qpsmtpd/SMTP.pm
--- qpsmtpd-0.96/lib/Qpsmtpd/SMTP.pm	2016-04-15 17:08:57.630842467 +0200
+++ mezzanine_patched_qpsmtpd-0.96/lib/Qpsmtpd/SMTP.pm	2016-04-15 17:07:45.577836505 +0200
@@ -96,6 +96,11 @@
 
     # this should maybe be called something else than "connect", see
     # lib/Qpsmtpd/TcpServer.pm for more confusion.
+    my ($rc, $msg) = $self->run_hooks("set_hooks");
+    if ($rc == DENY) {
+      $self->respond(550, ($msg || 'Connection from you denied, bye bye.'));
+      return $rc;
+    }
     $self->run_hooks("connect");
     return DONE;
 }
@@ -309,7 +314,9 @@
           && $self->transaction->notes('tls_enabled'));
 
     if (exists $auth_mechanisms{uc($mechanism)}) {
-        return $self->{_auth} = Qpsmtpd::Auth::SASL($self, $mechanism, @stuff);
+        $self->{_auth} = Qpsmtpd::Auth::SASL( $self, $mechanism, @stuff );
+        $self->run_hooks("valid_auth") if $self->{_auth} == OK;
+        return $self->{_auth};
     }
 
     # no plugin implementing this auth mechanism