Privacy is the key and it’s not only in our private life but also in business. If you using Gmail (Google Workplace) for your business, something called read receipt is an odd thing.
Many businesses however are using solutions from Microsoft called Microsoft 365 Business (in various plans).
Microsoft, in their subscription service, provides a lot of useful functionalities, but there are some functions, that are heading back to times when Microsoft Outlook started gaining popularity (Microsoft Office 97).
Through these functionalities there was one, requesting a receipt sent back to the sender when the recipient read an email.