I am using the Microsoft.Office.Interop.Outlook.Application to generate an email and display it on the screen before the user can send it. The application is a
To get/set the user's default signature you can use the windows registry.
Example for Outlook 2010:
HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Common\MailSettings
Name: NewSignature
Datatype: String
Value: (name of signature file without ending)