logstash shipper skipping postfix/smtpd

shipper.conf

input {

  tcp {
    port => 55514
    type => "jenkins"
    format => json

  }

}

filter {

  grep {
    match => [ "@message", "postfix" ]
    negate => true
  }

  grep {
    match => [ "@message", "Connection closed by 127.0.0.1" ]
    negate => true
  }

}

output {

  stdout {
    debug => true
    debug_format => "json"
  }

  redis {
    host => "127.0.0.1"
    data_type => "list"
    key => "logstash"
  }

}