In Outlook 365, when an email has blocked content and you click on the "I trust content from <source>" link to whitelist the source, where is this setting stored?

The problem I'm having is that I use CCleaner and there's something it is cleaning that wipes all these settings so that when I go back into Outlook 365, I'm back to the blocked content email view with the link that allows me to trust/whitelist the source.

I figured that the settings would be stored in cookies so in CCleaner I tried whitelisting all the Microsoft/Office domain cookies, but that still did not work.

I just want to know which folder location(s) and/or cookies and/or whatever that contain Outlook's trusted source settings so that I can configure CCleaner to bypass those folders/cookies/whatever when it is cleaning.