Acompli

Acompli
source
Name	Acompli
Developer	Acompli, Inc.
Released	2014
Discontinued	2015
Replaced by	Outlook Mobile
Operating system	iOS, Android
Genre	Mobile email client
License	Proprietary

Acompli was a mobile email client application launched in 2014 that combined email, calendar, and file-management features for enterprise and personal users. The app integrated with major cloud services and aimed to simplify workflows on smartphones by unifying mail, calendar, contacts, and attachments. Developed by a startup founded by former executives from Microsoft and Salesforce, the product drew rapid attention from technology companies, investors, and media before being acquired in 2015.

History

Acompli was founded in 2013 by executives with prior roles at Microsoft, Yahoo!, and Salesforce, backed by venture capital from firms such as Redpoint Ventures, Felicis Ventures, and Y Combinator. The company announced a public beta in 2014 and launched on iOS and later on Android, positioning itself against incumbents like Gmail (service), Apple Mail, and third-party clients including Spark (email client) and Nine (mobile email). Early press coverage compared Acompli to enterprise-focused services like Microsoft Exchange and Google Apps for Work because of its integrations with Exchange ActiveSync and Office 365. In late 2014 and early 2015, Acompli expanded features and attracted attention from major technology corporations, culminating in its acquisition by Microsoft in December 2014, announced in late 2014 and completed in 2015.

Features

Acompli combined inbox management, a unified calendar view, and file access in a single interface. The app supported multiple account types including Exchange Server, Office 365, Gmail (service), and Yahoo! Mail while offering threaded conversations and swipe gestures inspired by clients such as Mailbox (app). Users could view calendar events from Google Calendar, Outlook Calendar, and Exchange Server within the same workflow and create or edit events linked to emails. Attachment handling included direct access to files stored on Dropbox, Box, OneDrive, and other cloud repositories, enabling inline previews and quick sharing. Search functionality leveraged server-side search for large mailboxes and integrated contact lookup across Active Directory and Google Contacts.

Platforms and Compatibility

Acompli released native applications for iOS and Android, supporting a wide range of smartphone models from manufacturers such as Apple Inc., Samsung, HTC, and Motorola. The client interoperated with enterprise infrastructures including Microsoft Exchange Server, Office 365, and IMAP/SMTP providers. Integration with cloud storage providers allowed interoperability with OneDrive, Dropbox, Box, and Google Drive. Mobile device management compatibility enabled deployment inside organizations using tools like MobileIron and AirWatch, and its support for Exchange ActiveSync facilitated use in environments running Microsoft Exchange Server 2010 and Microsoft Exchange Server 2013.

Acquisition by Microsoft

In December 2014, Microsoft announced the acquisition of Acompli, citing a strategic plan to enhance mobile productivity across Windows Phone, iOS, and Android. The move followed previous Microsoft acquisitions of mobile-focused companies such as Sunrise Calendar and mirrored Microsoft’s broader investments in cloud and productivity services including Office 365 and Outlook.com. After the acquisition, Acompli’s team and technology were integrated into Microsoft’s mobile software organization, and the Acompli app was subsequently rebranded and relaunched as Outlook Mobile in 2015, aligning with Microsoft’s unified messaging and calendar strategy.

Reception and Impact

Industry reviewers and technology publications compared Acompli favorably to established mobile clients, praising its unified inbox, calendar integration, and attachment workflows in outlets such as The New York Times, The Verge, TechCrunch, and Wired. Analysts noted Acompli’s influence on design patterns adopted by competitors including Gmail (service), Apple Mail, and third-party clients like Spark (email client) and Newton Mail, particularly in prioritizing attachments and calendar actions. The acquisition by Microsoft was analyzed in business press alongside other high-profile deals such as LinkedIn and GitHub, seen as part of Microsoft’s shift under its executive leadership toward cross-platform services.

Security and Privacy

Acompli implemented security mechanisms appropriate for enterprise email, including support for Exchange ActiveSync policies, TLS encryption for server connections, and remote wipe capabilities compatible with Mobile Device Management suites. Its handling of credentials and attachments was subject to scrutiny from privacy advocates and corporate IT departments, who compared practices to industry standards set by Google LLC and Apple Inc.. Post-acquisition, Microsoft applied its corporate security and compliance frameworks—aligned with certifications such as ISO/IEC 27001 and regulatory regimes like EU-U.S. Privacy Shield (then active)—to the mobile offering.

Legacy and Succession

Following its integration into Microsoft, the original app’s concepts persisted in Outlook Mobile and influenced features across Office 365, Exchange Online, and companion apps such as Sunrise Calendar (prior to its discontinuation). Acompli’s emphasis on converged workflows and cloud-file integration informed design directions at competitors like Google LLC and inspired newer clients including Spark (email client) and Newton Mail. The acquisition is often cited in analyses of startup exits in the productivity software sector alongside deals involving Mailbox (app) and Sunrise Calendar, marking Acompli as a notable case in mobile-first enterprise application evolution.

Category:Email clients Category:Microsoft acquisitions