If a DWA message disclaimer is set and a DWA user sends an email where the recipient is an internal user - i.e. address is Notes mail format not internet format, the Notes user receives the message disclaimer.
This is a known behavior in Notes/Domino and reported to Quality engineering in SPR # KBRT67FN7B as an Enhancement request and currently there are no plans to address it in R8 and R8.5
