If you are getting notifications from OptionPreview, then your Mac is infected with adware. OptionPreview is adware for Mac.
OptionPreview changes setting in your Mac. First, OptionPreview installs a browser extension in your browser. Then, after OptionPreview 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.