Google has been on the forefront of email technologies ever since the beta of Gmail, long, long ago. They’ve always been able to efficiently identify and categorize mail, including spam to help keep your inbox clean. Although no solution can keep your inbox spotless, Gmail comes close.
Last August they introduced what Google calls your “Priority Inbox”. Essentially, Google felt that most inboxes were fairly cluttered with non-important messages — I’d have to agree. To remedy this, the Priority Inbox attempts to identify which messages (and which people) are important, and gives them special treatment.
Google rolled out the new Priority Inbox first to their desktop browser client, then later to their Android client. With their recent announcement, now any mobile browser that’s HTML5 compatible should be able to use Priority Inbox as well.
Source: Google Mobile Blog