1. Boost your productivity with reliable access anywhere with services like email, calendar, file sharing, meetings, instant messaging, and Office Online

  2. Secure premium email service with mobile sync apps for calendar, contacts, tasks, notes and FISMA compliant email archiving.

  3. Collaborate for free with online versions of Microsoft Word, PowerPoint, Excel, and OneNote. Save documents, spreadsheets, and presentations online, in OneDrive. Share them with others and work together at the same time.

  4. SOGo is groupware server with a focus on scalability and open standards.

  5. Horde Groupware is a free, enterprise ready, browser based collaboration suite.

  6. Mailbird is the best email client for Windows 7, 8 and 10

  7. Google's encompassing suite of cloud-based business apps.

  8. maildrop is a Mail delivery agent used by the Courier Mail Server. The maildrop MDA also includes filtering functionality. maildrop receives mail via stdin and delivers in both Maildir and mbox formats.

  9. iCloud is cloud service done right. It stores your music, photos, apps, calendars, documents, and more. And wirelessly pushes them to all your devices.

  10. eM Client is a Windows-based email client for sending and receiving emails, and managing calendars, contacts and tasks.

  11. Pictle is a simple, beautiful way to send secret images.

  12. Disposable email address application.