Signature Warning

This policy setting controls how Outlook warns users about messages with invalid digital signatures. If you enable this policy setting, you can choose from three options for controlling how Outlook users are warned about invalid signatures: - Let user decide if they want to be warned. This option enforces the default configuration. - Always warn about invalid signatures. - Never warn about invalid signatures. If you disable or do not configure this policy setting, if users open e-mail messages that include invalid digital signatures, Outlook displays a warning dialog. Users can decide whether they want to be warned about invalid signatures in the future.