Information
This policy setting allows you to prevent Outlook users from adding signatures to e-mails they create, reply to, or forward.
If you enable this policy setting, Outlook users cannot manually add signatures to e-mails they create, reply to, or forward, nor will they be able to configure automatic signatures.
If you disable or do not configure this policy setting, Outlook users can add signatures to e-mail messages either manually or automatically. The recommended state for this setting is: Disabled.
Rationale:
By default, Outlook users can create and use signatures in e-mail messages. Users can add signatures to messages manually, and can also configure Outlook to automatically append signatures to new messages, to replies and forwards, or to all three. Signatures typically include details such as the user's name, title, phone numbers, and office location. If your organization has policies that govern the distribution of this kind of information, using signatures might cause some users to inadvertently violate these policies.
Solution
To implement the recommended configuration state, set the following Group Policy setting to Disabled.
User Configuration\Administrative Templates\Microsoft Outlook 2013\Outlook Options\Mail Format\Do not allow signatures for e-mail messages
Impact:
The recommended settings do not change the default configuration of Outlook, and therefore should not affect usability.