Is this an imap account ? Try:

• right click on mail account name folder in Folder Pane and select 'Subscribe'
• click on 'Refresh'
• Select folders and click on 'Subscribe'
• click on 'OK'

Hi Toad-Hall. This is an imap account. Thanks for posting. Did as you said but unfortunately no luck. My folders are still empty.

what happens if you use Shift+F5 to get all mail?

Nothing happens Matt. All still empty.

I went onto Gmail website. All the folders there are also empty.

I tried contacting support but it seems to be impossible to do that.

re: I have installed some directories in Thunderbird in order to store emails by catagory.

I presume you mean you created some folders to organise emails.

re:I went onto Gmail website. All the folders there are also empty.

I presume you are talking about the 'labels' which are usually listed below the Trash or if viewed via Settings > Labels, they are at the bottom - system labels - categories - 'Labels'. Each of those 'Labels' would need to have the 'show in imap' checkbox selected.

I ask this because you mentioned 'category' and gmail does have 'Categories', but gmail's 'Categories' are not available via imap. So if you had used gmail 'Categories' and moved emails into those catagories, then Thunderbird cannot see them. If the gmail categories are hidden in gmail, try selecting 'show' to see if they display emails on server.

If you do mean 'Labels' and they are the same names as folders you would see in Thunderbird imap account and they are empty when viewed via gmail webmail, then Thunderbird cannot show something that does not exist. Imap accounts can only display whatever is on the server.

If emails got deleted then they would have shown up in the gmail Trash, so would be recoverable.

Idea: It is possible that somehow the emails lost their 'label' which means they may be archived in the 'All Mail' folder.

Logon to gmail webmail account via a browser and look in the 'All Mail' folder for emails that have no label. If you see them, you can reapply a label, so the email gets displayed again in the appropriate label. I've added an image below to show what I'm talking about and the process to use for one or several emails.

re: I have installed some directories in Thunderbird in order to store emails by catagory.

I presume you mean you created some folders to organise emails.

re:I went onto Gmail website. All the folders there are also empty.

I presume you are talking about the 'labels' which are usually listed below the Trash or if viewed via Settings > Labels, they are at the bottom - system labels - categories - 'Labels'. Each of those 'Labels' would need to have the 'show in imap' checkbox selected.

I ask this because you mentioned 'category' and gmail does have 'Categories', but gmail's 'Categories' are not available via imap. So if you had used gmail 'Categories' and moved emails into those catagories, then Thunderbird cannot see them. If the gmail categories are hidden in gmail, try selecting 'show' to see if they display emails on server.

If you do mean 'Labels' and they are the same names as folders you would see in Thunderbird imap account and they are empty when viewed via gmail webmail, then Thunderbird cannot show something that does not exist. Imap accounts can only display whatever is on the server.

If emails got deleted then they would have shown up in the gmail Trash, so would be recoverable.

Idea: It is possible that somehow the emails lost their 'label' which means they may be archived in the 'All Mail' folder.

Logon to gmail webmail account via a browser and look in the 'All Mail' folder for emails that have no label. If you see them, you can reapply a label, so the email gets displayed again in the appropriate label. I've added an image below to show what I'm talking about and the process to use for one or several emails.

Sorry Toad-Hall. I tried to change the colour of my replies to make them stand out but my replies are all the same (Black)

re: I have installed some directories in Thunderbird in order to store emails by category. I presume you mean you created some folders to organise emails. I do indeed re:I went onto Gmail website. All the folders there are also empty. Yes again. I’ll try and match the terminology.

I presume you are talking about the 'labels' which are usually listed below the Trash or if viewed via Settings > Labels, they are at the bottom - system labels - categories - 'Labels'. Each of those 'Labels' would need to have the 'show in imap' checkbox selected. I ask this because you mentioned 'category' and gmail does have 'Categories', but gmail's 'Categories' are not available via imap. So if you had used gmail 'Categories' and moved emails into those catagories, then Thunderbird cannot see them. If the gmail categories are hidden in gmail, try selecting 'show' to see if they display emails on server. "The issue here is ‘moved’." I didn’t touch them. The emails that I moved to the ‘LABELS’ section that I created, have been there for months if not a couple of years.

If you do mean 'Labels' and they are the same names as folders you would see in Thunderbird imap account and they are empty when viewed via gmail webmail, then Thunderbird cannot show something that does not exist. Imap accounts can only display whatever is on the server. I understand imap accounts are only a window to the server. This tells me they were deleted from the server. If emails got deleted then they would have shown up in the gmail Trash, so would be recoverable. I had a look in ALL the places they could be, but I can’t find any. Idea: It is possible that somehow the emails lost their 'label' which means they may be archived in the 'All Mail' folder. There are emails in ‘All’ but none from the Labels section. Logon to gmail webmail account via a browser and look in the 'All Mail' folder for emails that have no label. If you see them, you can reapply a label, so the email gets displayed again in the appropriate label. I've added an image below to show what I'm talking about and the process to use for one or several emails.

If I could get Mozilla to reinstall my emails from say a month ago it would be great. I'm sure they keep a backup.

re :If I could get Mozilla to reinstall my emails from say a month ago it would be great. I'm sure they keep a backup.

Thunderbird is not a server, it's just a program running on your computer and the emails are stored in a bunch of files on computer, so there would only be a backup if you created one.

Have you ever created a backup of the 'Thunderbird' folder in this location: C: Users/User Name/Appdata/Roaming/Thunderbird

OR Have you ever created a backup of the 'profile name' folder in this location: C: Users/User Name/Appdata/Roaming/Thunderbird/Profiles/'the profile name' folder

If you have a backup then I can advise on how to get them back into thunderbird by using the 'Local Folders' account and from there gradually uploading back onto server.

Gmail Help on REcovery: https://support.google.com/mail/answer/7015314?hl=en&co=GENIE.Platform%3DDesktop#zippy=%2Cmost-of-my-emails-are-missing At the above link.... Scroll down to 'The steps above didn't help' section Click on link text ' We can help find your missing emails and secure your account' that takes you to a section where you can then try to recover emails.

Good video: https://www.youtube.com/watch?v=9Mtbv7Ja3nc

Toad-Hall your knowledge is up there. Thanks for helping with this issue. Gmail Help on REcovery tool did the job. All emails are back.

Now I'll be looking at backing them up.

Cheers