I used to organize such things into a big folder structure by topic. Since it was mental effort to keep organized, I rarely did it and sometimes had tens of thousands of unsorted emails. Realized that if I needed to find something, I could always find it by searching, but sometimes an important mail fell through the cracks.

Now I stay on top of mail by sorting into “todo”, “follow up” and “archive”. I go through the first 2 every few days and archive anything I don’t care about, and move things from follow up to todo if I feel I need to do some action. Typically this means sending a reminder to someone.

You can probably sort through 500 emails in a couple hours. If that’s too daunting, just do 100 per day.

I disagree with others that say to delete your bookmarks. I would just archive them so you can find them by searching later if something triggers your memory. But from now you can save bookmarks in 2 folders. If something is interesting, save it in your archive and forget about if. If something is actionable or time sensitive, save it in a “todo”, “to read” folder or open tab.