You are using Dynamics AX 4.0 SP2 and Outlook 2003. Certain Reports (like Confirmations) your customer is sending out by E-Mail attached as PDF. In Outlook 2003 you have configured a Signature that is added automatically to each E-Mail. But in Outlook 2003 no Signature is added to the E-Mail created by Dynamics AX.
This is a limitation of Outlook when using the SimpleMAPI interfaces. This limitation is described in the following KB articles:
You can use one of the following workarounds: