Using older versions of Outlook for Mac for personal email and calendar
Thanks Jim
I was suffering from this issue (no attachments or inline images), which was resolved by upgrading to the 16.76 beta. However, it today started happening again.
"Turn on optional connected experiences" was checked. However, I found turning it off (restarting app) then turning it on (restarting app) fixed the issue again - at least for now.
I too have the Hubspot plugin installed, so wondering whether there is a weird interaction going on here.