[kanetrain]

Matt - If the search team or gmail team are using email engagement as an indicator of a site's reputation or usefulness... or even to grade the quality of email from a site, it's really problematic. This can so easily be exploited to hurt someone else's site. You just create thousands of fake gmail accounts, sign up for your competitor's newsletter with all of them, and then never open any of their emails. Presumably there are already people doing this... and making sure those "fake" account appear as real as possible so Gmail bots can't tell the difference.

[Matt_Cutts]

To the best of my knowledge, we don't use email reputation in any way in our search rankings.