How do I disable the confirmation email sent out from Drupal?

gistfile1.txt

In Drupal 7, the conf variable you should add the following line in your settings.php

  $conf['user_mail_register_no_approval_required_notify'] = FALSE; 

The bold could take this value:
  register_admin_created: Welcome message for user created by the admin. 
  register_no_approval_required: Welcome message when user self-registers. 
  register_pending_approval: Welcome message, user pending admin approval. 
  password_reset: Password recovery request.
  status_activated: Account activated. 
  status_blocked: Account blocked.
  cancel_confirm: Account cancellation request.
  status_canceled: Account canceled.

Be careful, it's user_mail_YOUR_VARIABLE_notify.