Connection limition from openfire to MSN?

We have adopped openfire and connected to MSN through IM gateway(gateway.jar).

After around 250 users connectd to the MSN through IM gateway, all the connections were dropped and none of connection was accepted after that.

I wonder if there is a connection limitation on free version of openfire(gateway.jar) or MSN.

imho msn, icq and stuff limits the connection from one source. it’s possible that msn block your server if they get too many incomming connections from external. this is only a guess. can be wrong but that’s what i’ve heared.