Microsoft Office Outlook is a powerful email client that can work with different email servers and provides many automation options. After releasing Office 365, which is a suite of cloud-based Microsoft Office apps and services, it became possible to use Outlook as a web application (Outlook Online) with Microsoft mail servers only. Outlook can sort incoming email messages to different email folders according to configured rules. For example, it can be configured to save spam messages in the Junk Email folder. Besides incoming mail, you can configure other custom rules.