Create or edit an existing signature in this folder, %APPDATA%\Microsoft\Signatures using Word according to your requirements.
TO SET THE DEFAULT SIGNATURE FOR A NEW EMAIL:
Add/Remove > Execute Computer Action > Registry Actions > Set a String Value
Registry KeyPath: HKEY_CURRENT_USER\Software\Microsoft\Office\XX.X\Common\MailSettings (The xx.x must be replaced by your Outlook version, simply open REGEDIT on any machine with Outlook installed and confirm the version number.)
Value Name: NewSignature
Is Expandable String: True
Value Data: Goverlan (This is the name of the Signature that was created in Step 1.)
TO SET THE DEFAULT SIGNATURE FOR A REPLY EMAIL:
Add/Remove > Execute Computer Action > Registry Actions > Set a String Value
Registry Key Path: HKEY_CURRENT_USER\Software\Microsoft\Office\XX.X\Common\MailSettings (The xx.x must be replaced by your Outlook version, simply open REGEDIT on any machine with Outlook installed and confirm the version number.)
Value Name: ReplySignature
Is Expandable String: True
Value Data: Goverlan (This is the name of the Signature that was created in Step 1.)