1.9.8.4.1 Ensure 'Add e-mail recipients to users' Safe Senders Lists' is set to Disabled

Information

This policy setting controls whether recipients' e-mail addresses are automatically added to the user's Safe Senders List in Microsoft Outlook. Sometimes users will send e-mail messages to request that they be taken off a mailing list. If the e-mail recipient is then automatically added to the Safe Senders List, future e-mail messages from that address will no longer be sent to the users Junk E-mail folder, even if it would otherwise be considered junk.
If you enable this policy setting, all recipients of outgoing messages are automatically added to users' Safe Senders Lists. If users respond to junk e-mail senders while this policy setting is Enabled, all future junk e-mail from the same address will be considered safe.
If you disable this policy setting, recipients of outgoing messages are not automatically added to the Safe Senders List. Users must explicitly add addresses to the list.
If you do not configure this policy setting, recipients of outgoing messages are not added automatically to individual users' Safe Senders Lists. However, users can change this configuration in the Outlook user interface. The recommended state for this setting is: Disabled.

Rationale:

Sometimes users will send e-mail messages to request that they be taken off a mailing list. If the e-mail recipient is then automatically added to the Safe Senders List, future e mail messages from that address will no longer be sent to the users Junk E-mail folder, even if it would otherwise be considered junk.
By default, recipients of outgoing messages are not added automatically to individual users' Safe Senders Lists. However, users can change this configuration in the Outlook user interface.

Solution

To implement the recommended configuration state, set the following Group Policy setting to Disabled.

User Configuration\Administrative Templates\Microsoft Outlook 2016\Outlook Options\Preferences\Junk E-mail\Add e-mail recipients to users' Safe Senders Lists

Impact:

In most situations, modifying this setting will have minimal effect on usability. However, if users send e-mail messages to many recipients, manually adding the recipients to a Safe Senders List might affect productivity. In such situations, you can choose to enable the setting for some groups of users.

See Also

https://workbench.cisecurity.org/files/553

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-6b.

Plugin: Windows

Control ID: 939d1f62d83ef81a1b870778aa81df7b1c56112ebea1c77e96b5c3a1ad3002ca