DTOO264 - Send all signed messages as clear signed messages must be configured.

Information

This policy setting controls whether Outlook sends signed messages as clear text signed messages. If you enable this policy setting, the 'Send clear text signed message when sending signed messages' option is selected in the E-mail Security section of the Trust Center. If you disable or do not configure this policy setting, when users sign e-mail messages with their digital signature and send them, Outlook uses the signature's private key to encrypt the digital signature but sends the messages as clear text, unless they are encrypted separately.

Solution

Set the policy value for User Configuration -> Administrative Templates -> Microsoft Outlook 2016 -> Security -> Cryptography 'Send all signed messages as clear signed messages' to 'Enabled'.

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_MS_Outlook_2016_V2R1_STIG.zip

Item Details

Category: SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|SC-8(1), CAT|II, CCI|CCI-000366, Rule-ID|SV-228455r508021_rule, STIG-ID|DTOO264, STIG-Legacy|SV-85855, STIG-Legacy|V-71231, Vuln-ID|V-228455

Plugin: Windows

Control ID: 98733276aef006886f205e9d63cd81b72a0e82da626d163900bc4a9635a3c4c7