Not all email services offer to request a read receipt when sending an email. On the other side not all mail services support to send a read receipt when email is read.
If you are using a Microsoft Outlook, you can request a delivery receipt or read receipt when creating an email, in Options
, ticking the checkboxes Request a delivery receipt
or Request a read receipt
If you are using Outlook on the web
(OWA), you can request delivery receipt or read receipt when creating an email, by clicking on the three dots on the top panel, going to Show message options and ticking the checkboxes. Options request a delivery receipt or request a read receipt may not be available, if you have a free @outlook or @hotmail account (if you don't have Exchange account or Office 365 account).
, you can request read receipt when composing a message, by clicking on arrow in the bottom right corner to show more options. Then you should choose Request read receipt. This feature is available only if using Gmail for work or school set up by an administrator. If you have a free @gmail.com account, read receipts won’t work.