[Thunderbird 128] Is it possible to unify the INBOX and SENT folders belonging to one account? I get a lot of e-mail requests to wildly varying topics and need to keep them organised by topic, date, etc. Thus I often want to store incoming requests (single e-mails or threads) and my answer(s) to them together in an offline (local) folder common only to that case. I do this by traversing the INBOX and the SENT folder separately and then moving corresponding items manually to the same offline folder. Since I have a super-hierarchical and massive offline folder structure, it takes a lot of time to navigate to the same folder twice, but I do not see how I can avoid that. Unifying INBOX and SENT folders would be a way out, I then have to traverse the combined folder only once. Maybe I am doing something wrong or have overlooked something trivial - I would be grateful if somebody could point that out, too.