I am trying to use "Flow" to automate emails every time a new item is added to a SharePoint discussion board.
This is working fine with all lists, however, it does not do anything when I create a flow for the discussion board. The name of the discussion board does not even come up as an option in the "List" category and if I use the "Documents" option instead of the lists, I am able to choose the correct discussion board, but the alerts do not work.
Discussions are based on the folder content type, with each reply to a parent discussion being an item within that folder.
Flow does not currently support many triggers or operations against folders (including discussion boards) in SharePoint sites, though they've been steadily adding functionality since Flow was introduced.
It's possible that this functionality will be added in the future. You can make suggestions and vote on proposed functionality in Microsoft's "Flow Ideas" community.