Does this really works? two points.. 
1. you should not return a confirmation if the user was found or not in the DB (for security reasons). Should always return a 201.
2. you should not wait for the email confirmation, maybe it will be sent async.

I think it could be something like:
user = User.find_or_initialize_by_email(params[:email])
user.send_reset_password_instructions unless user.new_record?
render status: :created