a) No. Yendif Login sends email after registration. Kindly get me your Joomla admin details. So, I can check what went wrong.
b) Have you enabled email verification ? If yes, the system will not login the user after registration and it will give message to activate his account from mail first.
Kindly get me your Joomla admin details to This email address is being protected from spambots. You need JavaScript enabled to view it.. So, I can check these ....
Also, I'm not able to reply you through email and I always receive a failure notice.