Microsoft Outlook Web App (or Outlook Web Access) is a browser-based email client. Outlook Web App (OWA) lets users access their Microsoft Exchange Server mailbox from almost any web browser. The tools has proven immensely popular, and in some cases organisations forego the deployment of desktop versions of Outlook in favour of OWA’s clean and intuitive presentation.
Additionally, OWA connects you to your contacts, calendars, tasks, and Office 365 tools like Sharepoint, Word online, Excel online etc., and other management facilities for handling your Office 365 accounts. Depending on user rights, some users have access to advanced services which permit network administration of in-house and third party installations.