Dynamics 365 button grayed out in Outlook

Hello,

I have installed Dynamics 365 app for Outlook in the desktop version of Outlook 2016. Everything seems to be working great, except that when I compose a new email, the Dynamics 365 button is grayed out.

The option is available when I create a new appointment, or reply to an email. But it appears gray when I send a message.

The documentation suggests that the button should be available when composing an email.

New email message:

New appointment:

I'va already tried the solutions given under this post but none is working

Any help would be greatly appreciated.

Thanks in advance

pidji