Hi is it possible when someone connects to the Wifi (hotspot), to send a popup message to the connected user on whitch i written something like greetings or something else, it is not comercial network it is a small wifi network...
You can use address list and web proxy for that purpose.
In is little complicate but it work on my network, make two rules first to pass IP in address list and other to redirect to web proxy. Make page on web server setup web proxy to redirect everything to your page and also on page create link to open some port to server passing Mikrotik.
In Mikrotik add in firewall rule to add in address list IP address opening that port.
When user connect to your network open browser will be redirect to your web page see page and after clicking some confirmation (confirmation is link to port used to add in address list) this IP address will be add in address list, after that user not be any more redirect to web proxy also define time in address list.
It will be much easier if we can use address list in web proxy rules I ask that support maybe they implement some time.
I thing you can to some thing using hotspot package and adverting option or trial user I experiment with that but after some time decide to use this way with web proxy and address list.