A recent member of the prominent hacking group Team Poison (TeaMp0isoN) is hawking what they claim is an exploit for the webmail system used by several prominent blue chip companies.

The former group member, known as Hex00010, said the undisclosed exploit allegedly in AtMail "allows full root access to the database allowing you also to view internal and external data outside of the main software".
The veracity of the claims could not be verified and Hex00010 did not respond at the time of writing.
However, the hacker claimed they would sell the "very high profiled exploit" to those they deemed skilled hackers.
AtMail boasts an impressive list of blue chip customers, including Virgin Atlanic, GlaxoSmithKline, FedEx, Cable and Wireless, and government agencies such as the US Department of Energy, and NASA.