Details
This setting controls whether Outlook users are allowed to send e-mail messages after they see an encryption warning.
If you enable this policy setting, encryption warning dialog boxes do not contain a Continue button, which means that users must cancel the sending operation entirely.
If you disable or do not configure this policy setting, if Outlook users see an encryption-related dialog box when attempting to send a message, they can choose to dismiss the warning and send the message anyway. The recommended state for this setting is: Enabled.
Rationale:
By default, if Outlook users see an encryption-related dialog box when attempting to send a message, they can choose to dismiss the warning and send the message anyway. If users send messages after seeing an encryption error, it is likely that recipients will not be able to read them.
Solution
To implement the recommended configuration state, set the following Group Policy setting to Enabled.
User ConfigurationAdministrative TemplatesMicrosoft Outlook 2013SecurityCryptographyDo not provide Continue option on Encryption warning dialog boxes
Impact:
Enabling this setting can cause disruptions if Outlook users attempt to send messages with encryption errors, although the errors themselves would likely cause disruptions in most cases if the messages were allowed to be sent.
Supportive Information
The following resource is also helpful.
This security hardening control applies to the following category of controls within NIST 800-53: System and Communications Protection.This control applies to the following type of system Windows.