Anybody who has been a part of the 700,000+ iPhone userbase and waiting to access the new Mailbox app for iPhone is in for some bad news.

Per reports, Mailbox, the third-party Gmail client, experienced a massive outage that lasted for more than 10 hours, and although the service has started to come back again for all existing users, it can still take a bit of time before the service regains full access.

Mailbox has been down for several hours, and has been delivering a "having trouble connecting" message to its fast-escalating multitude of users. On Twitter, however, developers attributed the hiccup to "an unusual server problem" and promised a fix in no time.

"Yep. sync issues have surfaced over the past 10 hours. we're cranking towards a fix," the tweet stated.

Developer Orchestra, Inc. of Mailbox, while rolling out the popular new email client, per The Verge, "played it about as safe as anyone possibly could. A long waiting list stands between iPhone owners and access to the sleek, innovative app. But today it's become clear that this phased approach has failed to shield Mailbox from complications."

The company has been rolling out the service in tune with the servers in cloud. The app relies on these servers to do things like send push notifications, make downloading email as fast as possible, and handle snoozed messages. The reason here is that if software is server-based, it is susceptible to being overloaded and the company wants to keep this from happening.

"At first, the pace may seem slow. This is by design. If we run into unexpected snags, we may even stop filling reservations temporarily. But as the service grows, we should be able to dramatically increase this pace until we no longer need a reservation system at all," the official page states.

However, with all the persistent problems related to the new outage, and the company having to issue "Having trouble connecting, please try again soon" messages, it has asked its user base not to worry and that "any messages that you take action on or any new emails you create should not be lost. Once we have resolved the issue your Mailbox will simply update and process all actions you've taken inside the app."

As of now, after the outage, the Mailbox performance seems to be returning to normal, though it appears the issues haven't fully gone away as of yet. It, however, can be assumed that it will be a matter of time before the service fully starts running as it should.