Hi,
Thank you for posting on Microsoft Communities.
The option is not available in Windows 10 mail app. I suggest you to give us a feedback using Windows 10 feedback app.
If you want to see the recipients, I suggest you to log into
www.outlook.com on your favorite browser and check the sent items for the recipients.
Hope this information is helpful.
Thank you.
What about if you are using Win 10 mail app as an email client for another service? Then there is no option to do the above. Seriously? This is RIDICULOUS Microsoft. I'm trying to run a small business and, of course, that involves sending group emails to
lots of blind copied contacts. How the hell am I supposed to know if they received it or not?