Hi Richard,

Yes, when you reply to, or forward and email from another client such as a mobile device using EAS or an Outlook client using IMAP you'll see the indicator within webmail also. In this example, I tested both the Forward and Reply functionality on the same email.  

I've been running accounts with both IMAP and EAS and haven't experienced the icons not displaying as expected.  If you're not seeing those I recommend ensuring you're on the latest release.  If there's still a display issue I would then recommend contact the support department through a support ticket so we can troubleshoot your environment.

I hope this helps!