After a few months building up hype with promises to revolutionize email, Mailbox finally launched its streamlined Gmail client for the iPhone last month, along a waiting line mechanism that quickly became absurdly long. They're not even done letting everyone in, but apparently they'll be getting help from another cloud-centric company with experience on scaling a service to support millions of users: Dropbox.

In a post over at the Dropbox blog, co-founders Arash Ferdowsi and Drew Houston explained their love for the service: "Like many of you, when we discovered Mailbox we fell in love---it was simple, delightful, and beautifully engineered. Many have promised to help us with our overflowing inboxes, but the Mailbox team actually delivered. After spending time with [Mailbox creator's] it became clear that their calling was the same as ours – to solve life's hidden problems and re-imagine the things we do every day."

Mailbox posted its own announcement on its website, echoing Dropbox's words about the two companies sharing goals and values. They also made it clear that Mailbox is not going away with the acquisition. Instead, they'll be able to scale the service, work on 'a host of new features', and add support for more email providers and mobile devices.

All 14 members of the Mailbox team will join Dropbox. Financial terms of the deal were not disclosed.

For those just hearing about Mailbox, the app is described as a completely redesigned inbox experience that will help you "put email in its place". Mailbox encourages you to use your inbox as a place to store only those emails that need your immediate attention. Everything else can be archived, deleted, added to a list or snoozed until a specific time or date with a quick swipe so you can focus on what is important at the time.

Orchestra, the company behind Mailbox, was only founded in 2011 and its first app Orchestra To-Do made Apple's top productivity app of the year. The company took a $5 million round of funding late last year from Charles River Ventures, Ron Conway's SV Angel, and Kapoor Capital, among others.

As a related note a new version of the Dropbox desktop client for Windows, Mac and Linux just came out.