That means you can mark messages as archived or deleted, compose new messages and replies, and even snooze messages to pop up again later, even if the app is, for whatever reason, unable to connect to the Internet. Underwood explained that this offline architecture "works for Airplane Mode, and if we have trouble in our system and have to take our servers offline temporarily."
The business of free
I've been using Mailbox for about a month, and--as I make clear in my review--I'm a big fan. But should customers be worried about the long-term viability of the app, given its $0.00 price tag? Underwood says no.
"We're really following in the footsteps of companies like Dropbox and Evernote, who have demonstrated their ability to make a good business out of a 'freemium' model. You give people a version of the experience for free, and have a series of premium features that more hardcore users can step up and pay for if they're interested."
As to what those premium features might be, Underwood is tight-lipped: "We have a lot of stuff in the pipe... But we're not talking about them yet, because part of the fun is revealing them over time."
Though he wouldn't spill about upcoming premium features, Underwood did offer a few peeks at where Mailbox is headed. "A native iPad experience is coming," he said. In fact: "Our goal is to get this app onto every device that people use email on, which means the desktop and Android and maybe other mobile devices as well."
Mailbox's primary limitation at launch is that it's limited to Gmail accounts. That limitation won't last forever, Underwood said.
"We had to focus with Gmail, but we architected the system so that we can add other email providers as we grow, relatively pain-free." Limiting the initial release of the app to the iPhone and Gmail, Underwood said, "is just a way for us to have a shot at getting an excellent email app out the door. The ante is so high for email, there's so much that you have to get right, that we had to constrain the process."
The acquisition question
The last company to try to reinvent mobile email was Sparrow; it ended up getting acquired by Google. I asked Underwood whether he expects acquisition might be in Mailbox's future as well.
Buyouts are "always a risk, to be honest," he said. Underwood pointed to situations that he thinks motivate acquisitions: "a product isn't going at a consistent scale, or isn't likely to grow into a big business, so the team needs to find a home for it, or find a home for the talent." While he acknowledged the possibility that Mailbox could face such issues, he said that "our hope is to build a big and real business out of this."
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