People? is that the address list in the compose windows (f9) or something else?

No help at all, and no idea!

Pops1 said

No help at all, and no idea!

Perhaps if you were to elucidate what it is you are talking about I or someone else could help you. You are correct. I had and still have no idea what you are on about so I guessed.

So lets start by you explaining what a "people" folder is. Thunderbird does not have one by default is the second thing you need to consider in your explanation. So some sort of information from you that makes it possible to guess what feature you are looking for or thinking about would really help.