>> some are getting everyday emails with 550 Relay not permitted
Is your domain pointing to the Webuzo server IP ? Is your hostname a fully qualified domain name pointing to the Webuzo server IP ?
What do the Exim logs have to say ?
Thanks Valley, its fixed now, i had to disable CSF and after that it was able to delete the ip's using GUI from Webuzo.
About the 550 relay not permitted, there is lots of errors saying "SMTP error from remote mail server after MAIL FROM" and its from postmaster http://postmaster.yahoo.com/421-ts01.html