A recently-discovered vulnerability in Gmail makes it susceptible to a “man-in-the-middle” attack that would allow a spammer to send thousands of email through Google’s SMTP service while also bypassing current security measures designed to prevent Gmail spam abuse.

A flaw in Gmail that allows spammers to send a potentially unlimited number of messages is definitely a problem, but there's another, external factor that could exacerbate any potential spam attack.

Not much more here.