Google dropped a surprise Wednesday, announcing that it's revamping a product that it hasn't revisited in a while: good old-fashioned e-mail.

The new service, called Inbox, lays down the heavy promise to conquer the problem of overflowing e-mail accounts -- a task that any number of apps have attempted, but few have accomplished. The fact is that while e-mail may get a bad reputation as the scourge of modern-day communication, it's still the primary way work gets done in an online world.

In Google's case, the effort to restore inbox sanity will rely on a few features. For one, the service will automatically bundle conversations into categories, using the same technology it introduced to Gmail inboxes last year to categorize e-mails from retailers or mailing lists. (Those changes, it should be noted, were not universally welcomed .) With Inbox, this will extend to grouping together e-mails by even more precise categories, such as receipts or bank statements. According to a company blog post, users can also teach Inbox to adapt the way it groups messages together.

Inbox will also give you highlights from e-mails to pull out the most important bits, such as real-time package tracking, phone numbers and flight times. Users can also set reminders and choose to have messages redelivered at a later time, as is offered already in apps such as Mailbox and Tipbit. Google will also infuse Inbox with a little of its own secret search sauce called "Assists," which provide information you may need to accomplish your to-dos, such as the number for the restaurant you have to call for a reservation.

Just to be clear, you can still use your existing Gmail address and receive messages through Inbox. Or you can just skip the whole experiment and keep everything the same. What Google is attempting here is a rethink of how we interact with e-mail.

The company put together a demo video, to show off exactly how the whole thing will work:

On mobile devices, the service seems to pull a lot of design cues from other e-mail apps that let you swipe left and right to accomplish different tasks.

Inbox seems to expand on a lot of existing Google projects. The company has worked harder to keep people on its own Web sites, rather than send them off into the Internet at large. Since 2012, for instance, a Google search leads to both results and a summary entry that attempts to directly answer a user's question. That feature saves time and keeps folks on Google's sites. Another project, called Google Now, pulls together both personal and public information when you search. For example, if you tell Google your favorite sports team, Google Now will show you scores and schedules of that team.

Inbox's interface echoes both of these approaches, but where it fits in Google's product lineup remains to be seen. Google made it pretty clear, however, that this is not part of some nefarious plot to kill Gmail, which boasts over 500 million users.

"Gmail's still there for you, but Inbox is something new," said Sundar Pichai, Google's senior vice president of Android, Chrome and Apps, in a company blog post.

Google is sending out invitations to Inbox starting Wednesday; those interested in getting one can send a message to  Pichai did not say when Inbox will be available for everyone. The service will work on Android and iOS devices as well as the Web.