To my knowledge, indexes get rebuilt automatically when a Content Author performs a Smart Publish and/or a Full Republish in Sitecore. That functionality does not seem to functioning as intended as we are having to manually perform a re-index, via the Indexing Manager, to see those items get added/modified/deleted in certain indexes.

My question is when specifically do the indexes get automatically rebuilt in Sitecore, and is there any setting in the .config's where this functionality can modified to NOT index automatically?