You can create folders and manually move messages to those folders. You also can create filters to automate this to some extent, but let's start with the folders.

Are you connecting to your mailbox using IMAP or using POP? In an IMAP setup, your folders, and message moves between your Inbox and a folder, are mirrored from Thunderbird back to the server. In Account Settings, you can choose which folders you might already have created on the server will be synchronized with Thunderbird. In a POP setup, your folders are purely local.

To check your connection type, you can use the Account Settings screen. Either:

• app menu button > Account Settings
• (tap the Alt key) Tools menu > Account Settings

I am on a desktop computer, on my brand new windows 8. Using POP. Just simply cannot find a way to set-up new folders. \them being local would be just fine. I saw somewhere that in the menu - under new - there "should" be a new folder option - but I do not have that option. My download of Thuderbird is very recent - I used Outlook before - but moving to new computer I no longer have a license for it. All functions I have seen so far in Thunderbird would be sufficient for my needs, but really need multiple storage folders. I would greatly appreciate your help. I am not very knowledgeable with computers. THANK YOU

I am so embarrassed - after looking everywhere for 2 days - I just found the way - and of course is super simple. In case anyone might read this.... just right click on the say "local folders" in the left panel - and there it is - create a anew folder. I kept looking in the menus :(

Thank you very much for your help