I don't know how to make this work :(
If mikrotik is the default gateway this will work without problems. But when the gateway is another device dst-nat does not work.
WAN (94.8.32.4/23) -> Mikrotik -> LAN (192.168.30.10/24) -> Mail svr (ip:192.168.10.2/24 gw:192.168.10.1)
/ip address
add address=94.8.32.4/23 interface=WAN network=94.8.32.0
add address=192.168.30.10/24 interface=LAN network=192.168.30.0
/ip firewall nat
add action=dst-nat chain=dstnat disabled=no dst-address=94.8.32.4 dst-port=\
25 protocol=tcp to-addresses=192.168.30.2 to-ports=25
/ip firewall filter
add action=accept chain=forward connection-nat-state=dstnat log=yes
I can use a rule, but I need real connection addresses for the mail server
add action=masquerade chain=srcnat dst-port=25 log=yes out-interface=LAN protocol=tcp to-ports=25
Any ideas are appreciated