Microsoft Outlook is an email and calendar app made by Microsoft. The desktop program first shipped in 1997 as part of Microsoft Office. Microsoft later moved its free Hotmail service to Outlook.com and released Outlook apps for iOS and Android in 2015.
Outlook handles email, calendars, contacts and tasks in one app. It works with Outlook.com accounts, Microsoft 365 work accounts and other providers such as Gmail and iCloud. The Focused Inbox splits important mail from the rest. Calendars can be shared, and meetings can include a Teams link. Rules and folders help people sort large volumes of mail. A new Outlook for Windows has replaced the older Mail and Calendar apps.
Outlook.com and the mobile apps are free with ads in the web inbox. Microsoft 365 subscriptions remove those ads, add more storage and include the full desktop app. Most large companies that run Microsoft Exchange use Outlook as their main email program. It is available on Windows, Mac, iOS, Android and the web, and it is one of the standard tools in offices across the US, the UK and Europe.