Joomla Email ActivationBy default, Joomla will send an email to a registered user to activate an account. For obvious reasons, this feature has many benefits. However, you have an option to remove this feature.
HOW TO NOT SEND A REGISTERED USER IN BACKEND/FRONTEND AN EMAIL:
To add users to backend without sending them an email,
1) Open the following file:
Near line 189, comment out the following line:
// JUtility::sendMail( $adminEmail, $adminName, $user->get('email'), $subject, $message );
In the Joomla administrator backend,
1) Click Site > Global Configuration > Click System Tab > New User Account Activation > Select 'No'.