Drupal: How can I automatically send an email to an user when I unblock him (status becomes active)?

How can I automatically send an email to an user when I unblock him (status becomes acti开发者_如何学编程ve) ?

I've searched the appropriate rule, but I couldn't find the correct condition (there is not a token with the user "status" or "block / unblock" property.

thanks

Add event: User account details have been updated
Add condition "Execute custom PHP code", write there code:

return !$account_unchanged->status && $account->status;

Add your action about sending email.