Office 365: Suppress Read Receipts
By default Office 365 will send read receipts when requested. This can be suppressed as follows:
- Log in at https://portal.office.com and go to the Mail app.
- Click the Cog in the top right corner and choose Options.
- Under General, Mobile Devices, tick Don't send read receipts for messages read on devices that use Exchange ActiveSync.
(This affects devices such as iPhones.)
- Under Mail, Automatic Processing, Read Receipts, select Never send a response.
(This affects the Outlook Web Access interface.)