From the outset this library (Soapbox from Coversant http://developers.coversant.net/) looked like the most promissing .NET library for the XMPP functionality of the MeAggregator. Unfortunately my beliefe in it has fallen to a low point. Although it is very extensive in its supported functionalities, there is one that is really not that useful. The Jabber ID (JID) is tightly locked to the URL of the Jabber server that you use, hence you can't login to one Jabber server using a JID from another server. This is a functionality that is used (I use it often myself) thus this library can't be used for the MeA work!
I've spent 1/2 day now looking at the possibilities of changingthe behaviour, but there seems to be way too many references to the fact that server is part of jid, and that the login server is that server.