I have described several configuration issues in the FAQ.pdf.
E.g. Joomla framework does not send emails when the senders address is not valid. When you have configured an invalid address in uddeIM, other components may use hard coded addresses, uddeIM will not send emails, the other components do.
There are some other issues, please check the FAQ.
uddeIM & uddePF Development
CB Language Workgroup
CB 3rd Party Developer