View email messages by conversation in Outlook - Microsoft Support
View email messages by conversation in Outlook. Outlook for Microsoft 365 Outlook 2021 Outlook 2019 More... By default, when you add most account types to Outlook, your messages are displayed in Conversations. A conversation includes all messages in the same thread with the same subject line.
Applies To:
Outlook for Microsoft 365, Outlook 2021, Outlook 2019, Outlook 2016, Outlook Web App for Office 365 Small Business, Outlook.com, New Outlook for Windows