Помогите! Мой dst-nat работает не так, как надо!

[admin@VTwall] ip firewall dst-nat> print
Flags: X - disabled, I - invalid, D - dynamic
0   ;;; Webserver
in-interface=pppoe-out1
dst-address=:80
protocol=tcp
action=nat
to-dst-address=192.168.0.6
to-dst-port=80
1   ;;; POP3
in-interface=pppoe-out1
dst-address=:110
protocol=tcp
action=nat
to-dst-address=192.168.0.6
to-dst-port=110
2   ;;; IMAP
in-interface=pppoe-out1
dst-address=:143
protocol=tcp
action=nat
to-dst-address=192.168.0.6
to-dst-port=143
3   ;;; HTTPS
in-interface=pppoe-out1
dst-address=:443
protocol=tcp
action=nat
to-dst-address=192.168.0.6
to-dst-port=443
4   ;;; Terminal Service
in-interface=pppoe-out1
dst-address=:63390
protocol=tcp
action=nat
to-dst-address=192.168.0.6
to-dst-port=63390
5   ;;; SMTP
in-interface=pppoe-out1
dst-address=:25
protocol=tcp
action=nat
to-dst-address=192.168.0.6
to-dst-port=25

[admin@VTwall] ip firewall rule voatec> print
Flags: X - disabled, I - invalid, D - dynamic
0   ;;; Allow established TCP connections
protocol=tcp
connection-state=established
action=accept
1   ;;; Allow UDP connections
protocol=udp
action=accept
2   ;;; Allow ICMP messages
protocol=icmp
action=accept
3   ;;; Allow smtp connections to server at 192.168.0.6
in-interface=pppoe-out1
dst-address=192.168.0.6/32:25
protocol=tcp
tcp-options=syn-only
action=accept
4   ;;; Allow http connections to server at 192.168.0.6
in-interface=pppoe-out1
dst-address=192.168.0.6/32:80
protocol=tcp
tcp-options=syn-only
action=accept
5   ;;; Allow POP connections to server at 192.168.0.6
in-interface=pppoe-out1
dst-address=192.168.0.6/32:110
protocol=tcp
tcp-options=syn-only
action=accept
6   ;;; Allow IMAP connections to server at 192.168.0.6
in-interface=pppoe-out1
dst-address=192.168.0.6/32:143
protocol=tcp
tcp-options=syn-only
action=accept
7   ;;; Allow SSL connections to server at 192.168.0.6
in-interface=pppoe-out1
dst-address=192.168.0.6/32:443
protocol=tcp
tcp-options=syn-only
action=accept
8   ;;; Allow Terminal Service connections to server at 192.168.0.6
in-interface=pppoe-out1
dst-address=192.168.0.6/32:63390
protocol=tcp
tcp-options=syn-only
action=accept
9   ;;; Reject and log everything else
action=reject
log=yes

Смотри, первые 5 правил переадресации портов (dst-nat) работают нормально, но последнее (SMTP) работает некорректно. Я пытаюсь подключиться к порту 25 командой telnet, кажется, подключение устанавливается, но разрывается через 2 секунды. Все подключения SMTP от внешнего почтового сервера разрываются. Помогите, пожалуйста.