If you are getting notifications from SearchResultsDelivery, then your Mac is infected with adware. SearchResultsDelivery is adware for Mac.
SearchResultsDelivery changes setting in your Mac. First, SearchResultsDelivery installs a browser extension in your browser. Then, after SearchResultsDelivery hijacks your browser, it modifies settings in the browser. For example, it changes the default home page, modifies search results, and displays unwanted pop-ups in your browser.