I bashed out a quick xenomail daemon yesterday. It is notified over jabber-rpc by a second script (it's not the best notification system and will be updated later) telling you whenever a new email comes in.
So far there exists xenonote, xenoremind, and xenomail. I'm not sure what my friend has working daemon wise. I know he was working on shell directory detection: a sort of directory sensitive notification daemon.
We'd like to make a release Mayish, so if anyone is interested in trying it out feel free to get the code from svn here: https://xentac.net/svn/xenophile/trunk/
If anyone has any questions, feel free to ask. I'm trying to drum up interest here people ;P