the support team of lunarpages.com answer my question
"Nothing has been changed on Pegasus (at least nothing that could cause this), but to be safe I have check the Chilisoft Email settings and restarted the server."
but still not working... the last change i made was the avatar mod.
i believe that did not work after that since this mod, i approved the users in "pending status" and i was waiting for their "activation", but the users never "activate their accounts", for that reason i check the registration process, and detect that the email to the user with the activation key is not working.
but "i didn't found" something about avatar mod makes problems with registration process....
I just registered as "test" on your site. Will you approve me and we will see if i get an email. If you get an error, please paste the exact error message.