You switched the hosting of your webpages and your e-mail. The old e-mail messages were on the e-mail server of your old hosting company. They stayed there.

When you created your e-mail address again with the new hosting company, their servers did not have that old e-mail.

Since Thunderbird was looking at the server for e-mail, when you switched servers, it couldn't see the old e-mail.

Before switching e-mail servers you should have saved all the e-mail from the old server to your "Local Folders" in Thunderbird, which would have saved them on your computer.

If you still have access to the e-mail servers for the old hosting company, then you can connect to it and download & save the old e-mail.

Get the person who helps you with your domain to help you do all this.

If you trusted the new hosting company to do everything for you for transferring your domain hosting, you put your trust in the wrong people. While webhosting companies will transfer your webpages (which are publicly available), they don't have access to your e-mail to transfer them. They probably told you this.

I appreciate your response, Bruce...but please know that I didn't "trust" my new host (Wix) to "do everything for me." I've been managing my own site and domain for several years, so I'm not some struggling newbie. That being said, it never occurred to me that neither my online storage nor my portable hard drive weren't saving my T'bird profile and files. My fault for not being more diligent, perhaps.

However, I have several subfolders in my profile folder, one of which (mail.joan***.com) contains several .msf files that have the names of the folders that disappeared. (For instance, Inbox, Sent, Junk, Trash, plus some other folders I set up.) There are NO .mbx files in that folder, however, although each of of .msf files has a correspondingly-named file that shows as simply "File" under "Type." Can I recover anything from this folder?

... it never occurred to me that neither my online storage nor my portable hard drive weren't saving my T'bird profile and files.

Your Thunderbird Profile with your e-mails are saved on your computer.

You were/are accessing your e-mail with IMAP and had the option set to save e-mails on your computer as well as on the e-mail server.

Before the mail host change, Thunderbird saw and synchronized all the e-mail between the server and Thunderbird. When you changed mail hosts, you used the same account in Thunderbird, just changing the server settings.

So when it connected to the new server, as far as Thunderbird was concerned, the account was was out of sync with the server. The new server did not have all the e-mail Thunderbird expected that would be there. So Thunderbird deleted all it's e-mails that were not on the server. All e-mail programs will do the same thing.

That's how IMAP is supposed to work. The server has a higher priority than the e-mail clients that connect to it. In normal use, if you use your phone to delete an e-mail from the server, you want that change to be reflected on the computer also, so you don't have to delete the e-mail from both locations.

That's what happened here. The server told Thunderbird that it didn't have any e-mails, so Thunderbird did what was necessary to match that state.

If you had created a new account in Thunderbird with the same address but the new server settings, and kept the old account in Thunderbird also, then the old account and the e-mails it had saved on your computer would have been safe.

On the subject of the files on the computer that hold the e-mail.

There are two files with the name of the Thunderbird folder. One has the extension .msf, and the other does not have any extension.

The file with no file extension is the "mbox" file which holds all the e-mails in the Thunderbird folder. The file with the extension .msf, is an index file that Thunderbird uses to keep track of the e-mails that are in the main file.

Chances are, since Thunderbird deleted all the old e-mails, the main "mbox" files will not have those e-mails anymore. But then again, maybe they do, if the .msf files have not been updated yet.

So:

1. Create a folder in Thunderbird under "Local Folders". Call it "Recover". Then in that "Recover" folder, create a subfolder with any name. This is so Thunderbird will create a file folder under Mail/Local Folders, called "Recover.sbd".

2. Quit Thunderbird.

3. Go to your Thunderbird Profile folder and copy (not move) all the "mbox" files (the ones with the names of the folders, but without a file extension), to the "Recover.sbd" folder under Mail/Local Folders. Do not copy over the matching .msf files.

4. Start Thunderbird, then go to the "Recover" folder. Thunderbird will build new indexes (.msf files), for all the new folders.

If you are lucky, maybe some of the old e-mails will be in those folders.

Other than that, the only ways to recover the old e-mails is:

A. If you had backed them up to another location other than your computer (like your portable hard drive?), and that backup has not been affected by Thunderbird on your computer now not having the old e-mails.

Try the same trick with step 3, but with the files from the backup.

Or,

B. Connect to the old mail server again (with a different "account" in Thunderbird), to download the e-mails again.

Two things.

1. Can you change DNS back to the old server. if you can get the email back into Thunderbird then you can save it so it is not lost. You identify MSF files, but mail is actually stored in files with the same name and no extension. From what has been said here you account was IMAP. It may be possible to get the mail from those folders with some messing about. But only if Thunderbird was keeping a copy on this machine in account settings. If you want to tinker, make a copy of all those "Just file" say on your desktop. Open them in notepad and do a search and replace on X-Mozilla-Status: 0008 (I am working from memory but 0008 is deleted. You might have to fiddle a bit to get the search format exact, but I did paste this from a read message and change the status.) Replace the status with 0000. So it would be find X-Mozilla-Status: 0011 replace with X-Mozilla-Status: 0008 Then install the import export tools add-on https://addons.mozilla.org/en-US/thunderbird/addon/importexporttools/ Use the add-on to import your edited data to a local folder.

Create a folder under local folders, Select it. Right click and select to import from the menu that appears.

It would be far easier to just change things back, make a download, use the addon to export the mail as MBOX and then re-import it. But it is up to you.

2. Wix only supply a single email address and you do not get to nominate what it is. I understand you can purchase more with their premium domains. But their pricing is fairly steep. compared to the likes of https://www.crazydomains.com.au/web-hosting/ Note also that the WIX cheapest hosting has Wix adds on your site.

Yeah, what Matt said.

I forgot about changing "X-Mozilla-Status".

I found "X-Mozilla-Status: 0019" for deleted e-mails and "X-Mozilla-Status: 0008" for e-mails that were moved out of the folder to another location.

Do a search and replace to replace them with "X-Mozilla-Status: 0000".

Thanks SO much to both Matt and Bruce! I haven't tried your solution yet because my computer was downloading a previous version of my profile from my cloud backup service.

As of this morning, the file downloaded and extracted...but now I need to test it out to see if I'm able to restore those missing files. So: what's your recommendation on how to do that? I can't very well replace ALL the files in my current profile with the files from that recovered profile, or I'll lose my more recent emails...just not sure how to proceed.

I hope it is not too late for this, but if you allowed Thunderbird synchronize to the new e-mail server after the backup recovery, the e-mails will be deleted yet again.

If it is not too late, then I recommend:

1. Installing MailStore Home to archive your current e-mails. It is a free program.

2. Disconnecting the computer from the Internet.

3. Reinstate the backup to your computer.

4. Run Thunderbird (without Internet connection), to see if your old messages are there. If not, then try another backup, or you are SOL.

5. If your old e-mails are there, then you can either run MailStore Home again, creating a new archive of the older mails in Thunderbird, or you can use my instructions from my post here about copying the files on your computer for those folders to "Local Folders".

6. Reconnect to the Internet.

7. Run Thunderbird. It will delete all the old e-mails again from your account.

8. Use MailStore Home to export the two archives back into Thunderbird under it's "Local Folders".

Thanks again, Bruce...so, do I presume from this suggestion that I NOT go through your original advice about importing into the "Recover" folder I created, and that I also ignore Matt's suggestion about X-Mozilla-Status? I won't be trying anything until Monday afternoon at the earliest.

I'm not saying to "NOT" do what I suggested earlier. I've offered alternatives, since your situation with backups in uncertain.

There are several choices here of what to do, depending on the exact state of your backups and your ability with computers and files.

Perhaps the easiest way would be best for you. That would be using MailStore Home with your backups.

If you are uncertain or uncomfortable with these things, and want some assurances of what you are actually doing, perhaps you would benefit from the help of a professional computer tech.