I've been working to implement a web-based file exchange system for work as an alternative to sending files through email. Early on we identified Open Upload as a good option for this. While the latest release 0.4.2 is stable, it is over a year old and there have been significant changes implemented in svn. It is a much better option.
While trying to build it for deployment, I discovered a flaw in the email notifications for invitations. The problem is the MIME message format is currently incorrect. After some exchange of email with the project lead I added two files invitationNotifytext.tpl and invitationNotifyHtml.tpl that contain the information needed to generate clean email messages.
In addition, I modified the uploadNotifyHtml.tpl and uploadNotifytext.tpl files to fix some minor typos. I'm attaching the files here in case you need them . once they are committed to svn, I'll remove these.