A few days ago, Microsoft sent a notice to users who had subscribed to the security updates which stated that as of July 1, 2014, the company will no longer send security updates, due to changing governmental policies concerning the issuance of automated electronic messaging.
The speculated reason, because of which Microsoft notified its users in the first place, is the new Canadian antispam law. The law states that no organization, including charities and not-for-profit organizations, is exempt from Canada's anti-spam legislation and regulations. And it carries penalties as high as $10 million for businesses and organizations.
Seems like Microsoft has sorted out the problem and will resume email-based security notifications. The next set of security notifications will be released this Thursday, ahead of the company's monthly Patch Tuesday.