I'd avise to backup your Thunderbird profile first.

Then you could try the following:

• Exit Thunderbird
• Delete all *.msf files in your Thunderbird dprofile folder and subfolders
• Delete or rename the global-messages-db.sqlite file in your profile
• Restart Thunderbird

It will take sometime but the files will be re-created while Thunderbird re-indexes all your email.

Thanks for the suggestion, Fabian. I have eight or nine profiles in my Tbird client, and I have this problem with just one of those profile, and only with the inbox folder at that. I deleted all the .msf files in just that profile ("dprofile" was a typo, right?), as well as "global-messages-db.sqlite" file, and had the same problem on restart.

Would going back and deleting all the .msf files from the unaffected profiles help in this case, do you think?

I also upgraded to OS 10.12 and am now running Tbird (52.7.0), but still have the same problem. Help!

Most people will only use one profile name folder which can contain many mail accounts. ~So, when you say profiles I think you mean mail accounts.

re :one particular Inbox folder You supplied good info showing all accounts, but which account number has Inbox with problem?

re: The inbox is quite large In the profile mail account name folder, do you see both of these files:

• 'Inbox' (no extension) file
• 'Inbox.msf' (index file)

What size is the 'Inbox' (no extension) file ?

Yes, I do mean mail accounts -- thanks for clarifying. The problem account is a gmail account, and I suspect it's account 5. But I just noticed an interesting problem here which is that I only see one gmail account in the "mail" sub-folder, when I would think there should be two. I don't think the account shown is the one with the bug, since the inbox file is only 19 MB, and it should be in the gb range. I'm wondering if the absence of this account in the mail sub-folder is why I can't get into the inbox -- before I attempted to delete the .msf files, I copied the profile folder, and there's only one gmail account in the mail subf-folder, too. However, I can access the sent mail and the drafts from that account, so I would assume that data is somewhere.

Actually, I believe I have found the proper account folder -- it is IDed as "incoming.verizon-1.net" and the inbox is 4.05 gb. Should I try deleting the .msf file there?

re: incoming.verizon-1.net...inbox is 4.05 gb. Should I try deleting the .msf file there?

Yes. But make sure Thunderbird is closed first. then delete the Inbox.msf file. restart Thunderbird.

Success! Thanks!

Recommend:

• create folders and move emails from Inbox into those new folders for organising.
• Delete any emails you do not want.

Usually, you do not need to empty the inbox before compacting, but as you had some issue last time, on this occasion, I would recommend that you move all of those emails into suitable folders and compact the folder when it is empty.

Note: Deleted emails are 'marked as deleted' and hidden, they are not completely deleted from file at this point. Compacting the folder will remove those deleted emails.

• To fully remove them and reduce file size, right click on Inbox and select 'Compact folder'.

I would also suggest :

• right click on Junk and select 'Empty Junk'.
• right click on Junk and select 'Compact folder'.

If you enable the 'Folder Pane Columns' you will be able to see file size in the Folder pane.

• 'Menu icon' > 'Options' > 'Layout' > select 'Folder Pane Columns'
• Then enable the 'Size' column.

See image below.

Thanks, this makes sense, though I have a Mac. I have done that before with another folder. But as long as you're here, let me ask two other questions, one related, one not -- this is TBird maintenance week in my house.

First, related: A month or two ago, the folder for a different email account was full and wouldn't download any more emails. I did as you suggested here, and moved several years worth of emails to an archive folder, and compacted. It took moving several years worth of emails and compacting each time before I could download new emails.

THEN shortly afterward, T-bird downloaded thousands of emails on the server that had already been downloaded. I had to delete those and compact the folders again. Not sure if this occurred because I was using version 45 of T-bird with Mac OS 7.5 or because of a new problem with the server, but it happened regularly since then -- though not since I upgraded to Sierra yesterday. If the upgrade doesn't fix that problem, do you have any suggestions?

Secondly, for this gmail account that is the subject of this thread, I have set my T-bird account settings to delete emails from the server when I delete them from T-bird. (Under server settings, I've checked "leave messages on server" and "until I delete them.") I delete emails directly from the inbox. But it is clear that deleted emails have remained on the gmail server. Any suggestions?

Thanks!

re :T-bird account settings to delete emails from the server when I delete them from T-bird.

Deleting from Inbox does not really them. You would need to compact the Inbox to remove them from the file. Then next time it accesses server those emails get deleted.

The trouble with gmail is that it does not act as expected. Gmail keeps all emails in the 'All Mail' folder. The Webmail Inbox shows emails that have the 'label' 'Inbox' set for emails in the 'All Mail' folder. This means it is possible to have the same email showing in different virtual folders.

Pop mail accounts can only access the server 'Inbox'. Gmail will only actually delete something that has been deleted and put into the gmail Trash/Bin which it will then auto empty every approx 30 days. Then it is removed from 'All Mail'. Deleting the Inbox label does not mean the same thing as it only removes the label and you can end up with eg: an empty Inbox but a full 'All Mail' folder !

Test: In Thunderbird

• Delete an email
• compact the folder to remove all traces
• click on 'Get Messages' to force access to gmail server

• Logon to gmail webmail via a browser

if already logged on then you need to refresh the browser to update the view.

Q: Has that email been moved into the Trash/Bin ? If yes, force the Trash/Bin to be emptied. Select 'All Mail' folder. Q: Has that email been removed from the 'All Mail' folder.

When dealing with email, I would also double-check look into the archived emails, in the web interface. Actually deleting email from GMail is not trivial.