Two years ago, Microsoft made a massive shift in the way it approached the email market. In January 2015, the company launched Outlook for iOS and Android, free professional-grade email apps for two platforms that Microsoft previously underserved in that regard.

Outlook for iOS and its Android sibling were special, because they supported Gmail, Yahoo and iCloud email, in addition to Microsoft’s Outlook.com, Office 365 and Exchange email offerings. While connecting to third party email providers isn't new for Outlook, offering one-click support for different email providers at launch sent a message that this wouldn't be locked to the Microsoft ecosystem.

The apps sported trendy features like the ability to archive messages or schedule them to reappear in a user’s inbox with the swipe of a finger. Outlook’s marquee functionality on mobile was a Focused Inbox that divided a user’s incoming messages by whether or not the app thought they were important — and it worked shockingly well.

This was a massive divergence from Microsoft’s past approach to offering email apps on platforms that competed with Windows. On iOS and Android, the only apps that bore the Outlook name prior to that launch were bare-bones Outlook Web Access clients. What wasn’t clear at the time was that the launch of Outlook mobile presaged massive changes for Microsoft’s whole email group.

Over the past few years, the Outlook team has focused on a new strategy that revolves around creating a cohesive experience that spans a user’s devices. Staying competitive in the email market is important for Microsoft because it’s facing competition from the likes of G Suite, with its machine-learning enhanced Inbox offering.

“Email has continued to be an integral part of business communications even in the day of messaging and social media,” Patrick Moorhead, a principal analyst with Moor Insights and Strategy, said in an email. “Many companies, including Google, are busy making improvements to email with projects like 'Inbox' and it’s important Microsoft stay near the cutting edge of it. They don’t have to lead in it, they just can’t be too far behind.”

Here’s how they got there.

Enter Acompli

Microsoft wasn’t starting from scratch with the new Outlook mobile apps. At launch, they were re-skinned versions and slightly modified versions of Acompli, a mobile email app that Microsoft acquired in late 2014. The acquisition was spearheaded by Executive Vice President Qi Lu, who was in charge of Microsoft’s Applications and Services Group.

Bringing Acompli in to launch a version of Outlook that would run on iOS and Android was in line with Microsoft’s overall strategy under CEO Satya Nadella, who rose to the top job slightly less than a year before the deal was done. Rather than abandon mobile operating systems that competed with Windows Phone, he pushed the company to embrace other computing platforms.

In addition to the Acompli app, Microsoft also got the team behind it. Javier Soltero, who was the startup’s CEO, was put in charge of Outlook's mobile apps following the acquisition. His co-founders, JJ Zhuang and Kevin Henrikson, both veterans of email service Zimbra, took up software architect roles inside Microsoft. Two years on, the three of them are all still at Microsoft, which is a rarity for acquisitions in the tech industry.

Acquiring Acompli gave Microsoft access to new real estate on users’ phones that the company didn’t have a play for previously, as well as a team that could help further its ambitions, according to Satish Dharmaraj, a managing director at Redpoint Ventures. Dharmaraj was instrumental in putting the Acompli team together. He introduced the three men who would go on to be co-founders, and led the only round of fundraising that the company took on.

“This is a team that knows how to disrupt and innovate and be more entrepreneurial, which I think is what Microsoft wanted, as they were looking to turn the corner and find their way back to the top of the innovation chain,” Dharmaraj said. “They did a lot of different moves, and this is just one small aspect of that.”

Scott Stiles, a 26-year Microsoft veteran who has been on the Outlook team for the past five years, said that he didn’t quite understand the importance of acquiring Acompli at first, but said that it has been a boon to the tech titan.

“From my perspective at least, it accelerated us by a year or two in terms of really having a competitive Outlook on those other platforms,” he said.

In addition to Acompli, Microsoft went on a spree of acquisitions focused on personal mobile productivity. The company picked up the makers of popular calendar app Sunrise in February 2015, and the company behind task manager Wunderlist in June 2015. Both groups have since been brought into the Outlook organization.

The Acompli team also brought a competitive perspective born from its heritage in the mobile app market. Soltero pointed out that getting users to install a new mobile email app is a high-friction problem, since Apple and Google both ship good clients of their own built into Android and iOS.

He’s working to imbue that same ethos across Outlook and the rest of Microsoft Office, as part of the strategy role he was promoted to in November of last year. Although IT departments, rather than individual users, often make the decision whether or not to adopt Outlook and other apps, Soltero said that “you can’t use that as an excuse to get lazy.”

Focusing on user experience seems to be working so far. The Outlook mobile app is consistently within the top 100 most downloaded productivity apps in the iOS App Store and Google Play Store worldwide. It often ranks among the top 10 most downloaded productivity apps in markets like the U.S., U.K. and France. Microsoft says that the app has over 40 million active users across iOS and Android.

Simplification and unification

One of the biggest projects over the past two years has been the unification of five different Outlook teams into a single group with a unified perspective. Stiles said that looking back, it’s possible to think of Microsoft bringing together the Outlook apps as a series of acquisitions, since they were often coming from different teams with different design languages.

“You have this team [in San Francisco] and elsewhere, the mobile team, that is able to move very quickly and has a very clear sense of direction and not as many expectations, frankly,” Soltero said. “And then you have these other teams that have been servicing hundreds of millions of users already, and have different versions and so forth.”

The teams have united under a banner of what they call “all-day use,” the idea that users should have an Outlook app available to them, no matter what device they use. The teams have also been working on building features that unify functionality across platforms, while making sure that each app best serves the platform that it’s built for.

“We’ve really shifted our focus to delivering experiences that sing across all the apps at once,” Stiles said. “We’ve delivered half a dozen features across all the apps in the span of a couple years, where if you were to rewind a decade before that, you’d see significant inconsistency across the platforms in terms of feature set.”

One of the things Outlook mobile has taught Microsoft is the importance of simplicity and approachability. Stiles said that mobile design sensibilities have been important in helping the company try to rework some of its desktop apps. That work has largely been subtle for the time being, with small additions like the addition of an Archive button that matches the functionality on the Outlook mobile app.

“I think we’ve really benefited from bringing some design talent on board from the mobile space,” Stiles said. “And it’s not just Acompli, we’ve got folks from around the company, and from outside the company, who have come in with deep mobile design sensibilities, and we’ve seen those be pretty powerful change agents as we look to modernize and simplify our PC apps.”

Soltero is so committed to ensuring the simplicity of the Outlook experience, he has even excluded one of his beloved features from the app. Acompli had a setting that let users perform different actions on an email address in their mailbox based on how far they swiped it over from one side or another in an inbox.

For example, swiping a message slightly right would archive it, while swiping further would delete it. While Outlook supports swipe-based filing, users can only assign one function to a swipe to the left or the right. While Soltero misses the two-stage swipe, he doesn’t see it returning to Outlook anytime soon.

He said it would be inconsistent of him to argue for the two-stage swipe, a complicated optional behavior, while at the same time pushing for increased simplicity.

The emphasis on user experience extends to the Outlook team’s work with other groups inside Microsoft. For example, the team behind the company’s Enterprise Management Suite and Intune mobile application management software wanted to display a “managed by Intune” label inside Outlook. Soltero argued that's not something users want to or need to know about, even if a company is paying to use mobile app management. The two teams sat down, and the Outlook team talked the Intune team into leaving it out.

Soltero said that while he wants Outlook to fit in well with business IT administrators, he doesn’t want that to hurt users.

“Too often, the desire for control and manageability and IT is done at the expense of the user and at the expense of the experience,” he said. “And it wasn’t an easy thing — we had to push back internally as we were evolving the products, both the [Enterprise Management Suite] stuff as well as the Outlook client and even the other Office 365 apps that use EMS — to make it known that it is important that the user isn’t punished for working at a company that wants security and wants manageability on their phones.”



As part of the unification project, Stiles said that the Outlook team is working on getting all of its apps running on the same core code, to help accelerate future feature development.

“That’s going to allow us to innovate faster, to share a ton of technology and a ton of learning in the service,” he said. “Architecturally, that’s actually a learning that we brought from the mobile application space, and we’re mapping to the desktop applications.”

Future features

The team’s focus on building Outlook for all-day use will carry into future feature development for its many apps. Stiles said that users shouldn’t think of one Outlook app as the canonical home of new functionality that other apps will follow.

For example, Microsoft recently announced that Outlook for Mac is getting native support for Office 365 Groups, something that the Windows app had for quite some time. Meanwhile, the desktop apps recently received the mobile apps’ Focused inbox feature.

Stiles said that users should expect the Outlook desktop apps to change over the next 12-18 months as the team works to tweak their designs toward greater simplicity.

“You’re going to see them be more approachable,” Stiles said. “You’re going to see them visually be a bit simpler without losing any of the power, but really start taking the approach of honing the application for the core scenarios of that app.”

On the mobile side, Microsoft recently launched support for add-ins, which allow third-party developers to integrate their applications with Outlook, so users can connect content from other systems to their mobile email.