how can I do that? I'm newbie =(
That's the problem with tutorials telling you
what to do but not annoying you with the
why.
What your existing mangle rules do is that they assign a
routing-mark (a routing table name), which leads in several subsequent steps to a choice of WAN interface for them, to all packets sent by a device in your LAN. These mangle rules make their choice solely based on source and destination addresses and ports of these packets; for all packets with everything in these four fields the same, the assigned
routing-mark is always the same.
But when a client in the internet connects to a server in LAN, it comes each time from another port. So for some connections, the responses of the server go via WAN 1, whereas for other ones, they go via WAN 2, regardless via which WAN the requests came in.
What you have to do is to use other mangle rules to provide a distinct treatment to these server responses, instead of the generic one provided by the per-connection-classifier rules.
One way is the one suggested by @aesmith - you would have two IP addresses, or two listening ports, at the servers, and let those additional mangle rules match on src-address and/or src-port; the other way is the one I've suggested in my first post, where you let RouterOS "note down" the WAN through which the client request come in, and use that note when assigning a
routing-mark to the response.