Hold possible duplicate invoices, link repeat quotes, check purchase forms. Every one is ready to run, and you can adjust it in plain language.
Put labeled client matter emails on a shared task list, one per thread.
Your marked Gmail conversations become shared Notion tasks, and finished work leaves your labeled inbox.
Put a clear next-day task beside flagged client correspondence.
See your next steps in the flagged-email task list, with action notes and due dates for tomorrow.