Hi,
By "the New Mail icon on the taskbar", do you mean the yellow envelope icon in the system tray? If this is the case, I'm afraid this is a known issue. I can reproduce it in my Outlook 2016 and this issue also exists in Outlook 2013. Currently,
we can try the following workarounds:
- Disable "Show an envelope icon in the taskbar" in File -> Options -> Mail, but you'll loose this functionality.
- Mark any other Email as unread and back to read and the envelope icon will disappear.
Thank you for your understanding.
Regards,
Steve Fan
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