Dropbox Inc, the cloud storage system said on Friday that it has purchased a new MailBox email app.

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 Gentry, Scott, and the team, it became clear that their calling was the same as ours at Dropbox—to solve life’s hidden problems and reimagine the things we do every day. We all quickly realized that together we could save millions of people a lot of pain.” DropBox wrote on its blog.

Under the deal, all 13 programmer, the company that makes the app, have joined Dropbox. Financial details were not disclosed.