Adding a server to favorites does let you connect sometimes if the server isn't appearing on your internet list.
Since you can't add the servers yourself, what you can do is get someone you know to rename their profiles.dat file, launch warband, create a character, and then add the servers you want to play on to the favorites list. Then they can send the newly created profiles.dat file to you, and you can use the character they created to access the servers you want to play on via the favorites list.
You could also use a hex editor to edit the IP of an existing favorite on a character, but that's more advanced.
This is a thread full of possible solutions to the Multiplayer server not populating.The developers are working hard on fixing this issue, but for now we have to rely on user made fixes to help the bug. Now these solutions may or may not work for you, they work for some people but not all.
1) from command line digit netsh winsock reset
2) Restart PC
3) Start M&B warband and enjoy multiplayer!
Submitted by Tanfata
1) Go to your routers setup page.
2)Uncheck both block IP flooding and block anonymous connections options
3) Start M&B Warband Multiplayer.
Submitted by Manatic
1.Launch game as usually go to the point where you get ''stuck'' (retrieving server list.. or connecting to a server)
2.wait few secs than press ALT+TAB go to start log off and switch user
3.Log back in in your account go back to game and what a surprise it WORKS
Submitted by Perkunas
1) Find the RGL_config.txt in your Warband Folder and Open it.
2) Find the max_number_of_connections and change the value from 64 to 20 or so.
3) Save and Start Warband
Submitted by the Developers
1) Find the RGL_config.txt in your warband Folder and Open it.
2) Find the use_secure_connection = 1 and change it to 0.
3) If it's already 0 change it to 1
4) Save and Start Warband.
Submitted by the Developers
1) Go into Multiplayer.
2) Host your own game and start Map and spawn.
3) Quit and press start search.
Submitted by TreeBeard
If all else fails
1) Close down any apps accessing the internet.
2) Start Warband windowed and go to the MP page where you can click 'Join a server'.
3) Start Wireshark.
4) On Window 7 my wireless adaptor is listed a simply "Microsoft", so Start capture on interface: Microsoft (On XP I think it listed the adaptor type)
5) Click on Join a server.
You will see a load of coloured entries showing up on the Wireshark screen, this process normally completes in a few seconds.
6) Click Capture, Stop. File, Saveas, etc.
You could zip and attach whole log to the bug report, its not very big or look for the "GET /handlerservers.ashx?" one Daegoth requested, right-click and select 'Follow TCP Stream'.
Props to Nood
One of the Dev's requested for you to do this and after doing so please post the results at the bug tracker which is located below.