I've heard rumors this actually might be the case.
Officially, Cutts in 2006 said this was not true...but this was ages ago and the verbiage he used was somewhat technical...
Someone recently suggested that a link sent to a Gmail account equals one link on one page. Also not true in any way.
(why use the term equals...why not say that google ignores all gmail links)?
To a certain extent, google data mining gmail for ranking information makes a lot of sense. I would assume this would only be for text emails and would probably have a throttle like page juice that prevents very active and/or new emails from distorting SERPs. But each email (properly filtered) with a link will have a lot of valuable contextual information not polluted by markup nor SEO gibberish of what that link is about.
Opinions on this? Anybody hear about or see any evidence that this is the case?