Re: C&C ultimate collection Red Alert 2 wont start
Origin isn't a game server, just an application server. It is completely unrelated to online play.
There are no real 'official' servers for RA2 left; they've been put in the hands of the community ages ago, and are currently managed by XWIS. There's a new online community springing up at CnCNet, though, and you might find more players there. The online system they are building for RA2 is still in development, but I believe a link to the beta client is on the forum. At the moment they only support Yuri's Revenge, though, since there is apparently little community interest in playing RA2 without the expansion's added units.
[2020 EDIT]
For anyone seeing this now, the RA2 CnCNet client has of course been finished ages ago now, and can just be downloaded from cncnet.org.
Do note that, since Yuri's Revenge has more recent maintenance by Westwood and fixes a load of bugs that vanilla RA2 still has, the CnCNet team chose to build their vanilla RA2 online play on the Yuri's Revenge game engine. So you still need Yuri's Revenge's to play the standard game online on CnCNet, and some game behaviour in the RA2 mode might still act like Yuri's Revenge due to changes in the game engine between the two.