emails not being sent through RTC 3.0

Hi friends,

I am using RTC 3.0 which initially was sending mails for workitem status changes, joining team invitations, etc but now it is not and when i try explicitly to send team invitations it fails giving an error saying governed by process, where as in porcess configuration i have given all permission and trying with user havin administrator privilidges. Also the email is configured properly and initially it was sending mails with same configurations. please help me out.

Regards
Satyam