These steps will place a copy of everything on one PC onto another: Here is the link for moving a profile in Windows when installed in default location:

https://support.mozilla.org/en-US/kb/moving-thunderbird-data-to-a-new-computer

here is the info in brief steps:

1. ensure thunderbird is NOT running on old machine
2. enter %appdata% in search window on task bar and press Enter key
3. this should open windows file explorer in Appdata\roaming folder
4. highlight the Thunderbird folder and copy to external media
5. ensure thunderbird is installed on second computer, started once and NOT running
6. enter %appdata% in search window on task bar and press Enter key
7. you should be in Appdata\roaming folder , copy&paste the exported Thunderbird folder there. This may prompt to overwrite an existing folder of same name. allow it
8. start thunderbird and all should be there

Reminder: Once you activate the POP account on second PC, the account on first PC will start getting out of sync. I suggest NOT using PC #1 after the profile has been exported, as that will immediately place the 2nd PC out of sync.

Thank you so very much, David. I had hoped to continue Laptop 1 in use in location #1 and Laptop #2 in Location #2. I also have Thunderbird loaded on my droid. My hope was to have all sync every time a change was made.

From your help comment, it appears that is not possible. Am I correct?

Again, so many thanks.

If you are wanting your phone and both computers to always be in sync, then IMAP is the only solution, because it does that automatically. With POP downloading only when active and NEVER syncing the sent folder, I recommend IMAP. It will remove any stress on managing this. The only caveat is that IMAP syncs TO the server. That is, if you delete a message from the phone or a PC, the message is gone for everyone. But that is the intent, keeping all together. On POP, if there is a message you want to delete, you would have to delete on the phone and also on each PC because each has a physically separate copy. Having stated that, if you use IMAP and decide to remove a message yet keep it, it's a simple matter of COPYing it to Local Folders on a PC and then delete it. Let me know your preference, and I will help you get to where you want to be. If both POP accounts are set to never delete messages, they should stay roughly the same. It's the timing of downloads that will affect how they relate. If messages are not high volume, the two will show the same content after a day or two. For example, if a message comes in, it will download on one laptop, but won't appear on the other IMAP accounts do this automatically. If I can assist further, just let me know.

YOU absolutely are a dear soul. I will come back when I am able to proceed. I think, but do not know, that I must use POP for my email client. I'll have to check on Monday. Many thanks.

You are very welcome. POP can work satisfactorily, but fails if you wish to send from one device and see the sent message from other devices. Most email providers support both POP and IMAP, but I can help you, regardless. If unsure, share the email provider name and I can assist. We do that regularly here. :)