Microsoft's main email client is Outlook, which comes in several versions, some of which offer a read receipt request option. If the sender accepts the read receipt request, you will be notified when your recipient reads the message. Here's how to enable read receipts in Microsoft Outlook.
How to Get a Read Receipt That Confirms Recipient Viewed Email in Outlook [Tutorial]
Outlook is Microsoft's full-featured personal information manager. Although it is primarily used as an email client, it also has calendaring, journaling, contact management, and other features. Outlook is available as part of the Microsoft Office/365 suite for Windows PCs and Macs, as well as Microsoft 365 online.
With Outlook on a Windows 10 PC, you can request read receipts for all messages you send or just for individual messages. Here's how to set the default for read receipt requests for all messages:
From the main menu, select File > Options.