I would recommend sending a note to ‘firstname.lastname@example.org’
It will depend on your microphone/input device to the built-in sound card, also the
specific motherboard and software you have installed.
This may just be a matter of clicking on the upper right corner of the screen and selecting ‘Settings’ Then from Settings select the ‘Sound’ and scroll down to Input devices and select which one.
Or if you are sound output, then select that instead and the speakers you have connected.