Exploiting Google MX servers as Open SMTP Relays Pablo Ximenes, Andr=E9 dos Santos May 07 2008
Vulnerability Report: As part of our recent work on the trust hierarchy that exists among email providers throughout the Internet, we have uncovered a serious security flaw in Ggoogle's free email service, Gmail. This vulnerability exposes Google's email servers in a way that allows an attacker to use them as open spam and phishing relays.
formatting link
Exploiting the Trust Hierarchy among Email Servers Pablo Ximenes, Andre dos Santos INSERT - Information Security Research Team University of Puerto Rico at Mayaguez (UPRM), USA; State University of Ceara (UECE), Brazil
formatting link