@bernatixer have a look at:
Deploy NodeBB in a subfolder of a site https://community.nodebb.org/post/43630
Hope it helps.
From this forum all emails going to Promotions folder (the worst one )
Has anyone tried solve it?
@evgeny-kurt Email from this forum does not go to any of my "junk" folders so I am going to suggest you may have a client side issue there? I avoid all things goog to the extent possible so no insights as to how to rectify but there should be a "not spam" button, or some kind of filter that needs tuning so it does not trigger on nobebb's community robot.
@gotwf promotions it's not "junk" that's why "not spam" button is not an option
Maybe someone how use gmail gets notifications from this community to other folders?