Microsoft Outlook is a personal information manager from Microsoft, included in the Office suite. It can be used as a stand-alone application, or can work with Microsoft Exchange Server and Microsoft SharePoint Server for online collaboration.
Outlook stores email messages, contacts, appointments, tasks, and notes in a .pst file. The .pst file format is a proprietary format for Outlook. When you back up your Outlook data, you back up the .pst file.
If you are using Outlook with an Office …