Note This change doesn't affect the SmartScreen filter online protection feature that's built into Windows, Microsoft Edge, and Internet Explorer. It also doesn't affect Outlook 2016 for Mac, which relies on server-side junk mail filtering and doesn't use SmartScreen spam filters.
Why is SmartScreen being deprecated in Outlook and Exchange?SmartScreen spam filters in Outlook and Exchange Server have become obsolete and have been replaced by Exchange Online Protection, which is a more effective, cloud-based email filtering service. Exchange Online Protection is built into all Office 365 and Outlook.com accounts and is available for purchase for on-premises Microsoft Exchange Server installations.
What happens on November 1, 2016?Microsoft will stop producing new spam definition updates to the SmartScreen filters in Exchange and Outlook. Existing SmartScreen filter and definitions will remain in place and will continue to provide some basic level of protection. The current definition will continue to junk some obvious spam emails. However, the filter will be ineffective in defending against the latest variants of spam.
For complete details, see Deprecating support for SmartScreen in Outlook and Exchange.