Popular email management app Mailbox has been acquired by file-sharing and storage service Dropbox. Terms weren't disclosed, but the company plans to keep Mailbox as a standalone app, though the companies plan to extend both their platforms going forward, reports The Wall Street Journal. "We felt we could help Mailbox reach a much different audience much faster," said Dropbox CEO Drew Houston, who said both companies shared the goal of making people’s lives easier. He said Dropbox will keep the Mailbox service running as a stand-alone app, and over time Dropbox will also use Mailbox’