Yes, I receive a notification offline via regular email that there is a message waiting on the website. I login, but there are no messages. I can send a message, but it never arrives in recipient's private uddeIM mail box.
I will write step by step and post it all here for you.
Sent a message from the test account to admin, it is stored in the database and available in the outbox. So it works fine.
When you are calling Joomla, do you have cookies enabled? Do you use and blocker, filter etc? Maybe something is filtered on your system (e.g. a plugin in your web browser), so the html form is not submitted correctly?
uddeIM & uddePF Development
CB Language Workgroup
CB 3rd Party Developer