"Robust search" is listed as the top feature. Is that really meaningful for something built upon Gmail which already outshines every other solution out there regarding search?
We're working on a non-standard search implementation that takes into account not only the terms you're searching for, but the type of emails your expecting your query to return (without adding additional operators or search complexity).
Our interface and the way we present emails on the page (contrary to traditional inboxes) decreases the importance of having phenomenal search algorithms.
