When you re-installed Thunderbird, did you delete your profile? You would have had to do it separately from installing Thunderbird.

If you did not, you don’t have to import from a back-up because your old profile is still in its original location.

If you did, then there are two ways of recovering your in-box. But you will need to find a pair of files in your back-up, one called inbox.msf and one called inbox without an extension.

What is inbox.ca?

There was no need to re-install Thunderbird.

The solution does not involve the tools menu.

Whoops, I typo'd - I meant the inbox file, no extension.

I think I didn't provide the proper context. I reinstalled Thunderbird to solve a different problem. But before reinstalling, I created the backup profile using Thunderbird's export function. I did not delete my profile, and when I reinstalled Thunderbird my existing profile mostly loaded, but only about a third of my Inbox emails appeared. To correct this issue I tried to import the backup profile I had made, but it was too big to load. So I manually unzipped the backup profile file.

After unzipping the backup profile, I had an Inbox. file and an Inbox.msf file along with many other files. I could find no way to import these two files via Thunderbird, so instead I copied the Inbox. and inbox.msf file into the Local Folders mail subfolder and rename them 'Backup'. I restarted Thunderbird, and it created a folder called Backup that contained 38 emails. Since the Inbox file (renamed 'Backup') is 6.3 GB, it appears almost none of the emails are loading into the new folder.

So I think I've figured out a way to import some of the Inbox file, but it is only partially working. If you have a second method, please let me know. Thanks!

Before doing anything else, I would try to figure out why your inbox is showing only about a third of your messages. What was the problem that led you to re-install Thunderbird?

Right click on the inbox folder, select "Properties", then click on "Repair folder". See if more messages appear.

If they do not, do the same thing with the "Backup" folder and see if more messages appear there.

If they do not, I am not optimistic about the second method. It is to get the add-on ImportExportToolsNG and use it to import the "Backup" folder. Please ask if you want more direction.

The original issue I tried to solve with the Thunderbird reinstall was a connection to my email server. For some reason, Thunderbird suddenly was unable to log into my email server despite having the correct settings. The test connection in 'Server Settings' worked, but Thunderbird could not connect to the server. I knew the server was fine as I could log in using Outlook or the server's online login. So one suggested solution was to reinstall Thunderbird, which, incidentally, has not solved the issue. So now I have Thunderbird not connecting and lost email - a real success on my part.

Anyway, I already tried the Repair folder tactic, but it did not produce any more email messages. I think the Inbox file was corrupted. I'm going to try the ImportExportToolsNG option as a last resort. Thanks for al your help!

Well, wait a minute. Maybe the connection problem is why your inbox is missing messages and we should try to fix that problem first.

Please report your incoming and outgoing server settings. Incoming server settings are in account settings > server settings. Outgoing server settings are in account settings > click on account name > edit SMTP server.

We will need this information for each server:

server name port connection security method authentication method username: just report if whether or not you are using your full e-mail address

Does your e-mail service provider require an app-specific password (aka security password, app password)?

No, re-installing Thunderbird does not fix connection problems.

Are you using anti-virus software?

Did you try to repair the back-up folder too?

The settings are as follows:

Incoming Server: pop.shaw.ca Server Type: POP Security Type: SSL/TLS Port: 995 Authentication: Plain text or Password

Outgoing Mail Server: mail.shaw.ca Server Type: SMTP SSL: on Port: 587 Authentication: Plain Text or Password

Username is my full email address.

When it was functioning, Thunderbird would connect to the server, prompt me for my password, and then log me in. Now it does not connect.

I do use antivirus software, but I disabled it and the firewalls to see if those may have been the issue - no luck.

As for the few recovered emails, most are from 2016 to 2020 with a few from 2024 and 2025. I find this weird, as I don't recall having any emails that old in my Inbox.

And yep, I tried repairing the backup file as well.

Do you get an error message related to connecting?

I found this on the Web:

In the Webmail page go to preferences>mail. Near the bottom of the page is a section for "Access from other mail clients" and you need to check "enable POP access".

Do you have that setting set?

Do you leave messages on the server? If you do, does the server show the messages that you consider missing?

A better test than disabling your anti-virus is to start Windows in safe mode with networking and see if the problems persist.

After you install the add-on, right click on "Local Folders" in your folder pane, select the add-on in the drop-down menu, and follow the menu options to import an mbox file. I'm eager to hear what happens because, after that, I'm out of ideas.

Do you have a general back-up of your drive that contains your Thunderbird folder with your profile? (You should!).

Oh, Buddy, you're a GENIUS! I enabled pop access, and that fixed everything! I have no idea why that was suddenly not on, and I didn't even know it existed!

Yes, I do have general backups of my drive; I make one every week. I'm old enough to remember regular mechanical hard drive crashes and learned that lesson long, long ago.

Thanks so much, Rick, you saved my bacon.

I wonder if the change happened after Rogers bought Shaw. Just a wild guess. Or you accidentally unchecked that option when you were using webmail, if you ever do use it.