>>When I tried to unsubscribe from the list on this page (https://sourceforge.net/projects/lammps/lists/lammps-users/unsubscribe), after entered my email address and clicked the 'unsubscribe' botton, there was no email received in my email box. As a result, it seems I cannot know my status of subscribing now.
Yeah, I never got an email when I tried to unsubscribe either. But when I tried to subscribe again after trying to unsubscribe (using the same email address) I did get an email. Strange, I know… but it worked for me.