I have Windows mail and it's set up correctly as default email.
I can select a file in Windows explorer, right-click, point to "send as adjoint" and it works
BUT when the file is opened in Word, then the "send" option leads to a window where the email option is not activated (light gray) and thus cant be selected
I've read another similar thread by Ronnycopeh but in his case, there was no default mailer, he set it and then it worked. Not my case.

thank you

Eto Demerzel