Codex tools: Log in
Sends a welcome email to new users after they have activated their account, it includes their username and password in the email for confirmation purposes.
<?php wpmu_welcome_user_notification($user_id, $password, $meta); ?>
wpmu_activate_signup calls this function to send the welcome email to the user, the parent function handles the activation of the end users account.
wpmu_welcome_notification does the same thing except that it is for who registered for an account and for a blog.