I constantly struggle with to-lo lists. Over the past 20 years I've tried so many different approaches to fix my procrastination and forgetfulness. What I've learned is that I suffer 'list-blindness' - if the list is on display in front of me all the time, I stop seeing it, and therefore do not action anything. If the list is in a book or an app, that I have to open, I forget to do it. Additionally, if there's too much friction to adding something to the list, the list never gets updated. Flagged emails suffer in the same way; I just ignore the flags. I'm my own worst enemy I know that, I just need to find something that works [for me].
Most important point IMHO:
> "If an email requires an action from me, it should go to my inbox so I can prioritise it. If an email does not require an action from me, I should not be getting it."