re :The files are still there after exiting Thunderbird, but on the next start-up of Thunderbird, the two Inbox.msf files disappear. What Anti-Virus do you use?

Do you have your Anti-Virus product scanning Thunderbird folders on start up ? Do you allow AV to scan incoming/outgoing mail ?

Do you use a program like CCLeaner ?

Is your thunderbird profile stored in the default location ?

Are you talking about IMAP or POP mail accounts?

If you start Computer in 'safe mode with networking' and then start Thunderbird, do you get the same issue?

Toad-Hall said

re :The files are still there after exiting Thunderbird, but on the next start-up of Thunderbird, the two Inbox.msf files disappear. What Anti-Virus do you use?

Microsoft Security Essentials

Do you have your Anti-Virus product scanning Thunderbird folders on start up ?

I don't believe so (how would I tell?).

Do you allow AV to scan incoming/outgoing mail ?

I don't believe so (how would I tell?).

Apart from any automatic updates that may have come down (for Thunderbird or for Microsoft Security Essentials) I've changed nothing in Anti Virus settings between everything working and the current state.

Another thing I notice is that the count of messages in a folder is not displayed after some distance down the folder tree (see attached screen shot) - the count of messages stops from the folder "Silk Rally Radio" onwards. If that is not a standard Thunderbird feature then I think it is probably coming from the "Manually sort folders" add-on/extension.

If I select one of the folders that is not displaying a count of total number of messages, then the status line displays "Building summary file for xxx..." (where xxx is the name of the folder) and then after a time which depends on the size of the folder, the total number of messages is displayed.

I have several years worth of emails for multiple accounts in this Thunderbird installation - I wonder if I have hit some limit on total size of messages or total number of folders, perhaps?

Do you use a program like CCLeaner ?

No.

Is your thunderbird profile stored in the default location ?

Yes - C:\Users\david\AppData\Roaming\Thunderbird\Profiles

Are you talking about IMAP or POP mail accounts?

POP3 accounts.

If you start Computer in 'safe mode with networking' and then start Thunderbird, do you get the same issue?

I'll try that and report back.

DavidJames said

Toad-Hall said

re :The files are still there after exiting Thunderbird, but on the next start-up of Thunderbird, the two Inbox.msf files disappear.

If you start Computer in 'safe mode with networking' and then start Thunderbird, do you get the same issue?

I'll try that and report back.

The behaviour if started in "safe mode with networking" is the same - error messages complaining that the summary files for some of the Inboxes cannot be loaded, no address books present, and the total message count not displayed for some folders.

OK that rules out interference from other programs on computer.

Please restart Thunderbird in Safe Mode. In Thunderbird Help > Restart with addons disabled.

Toad-Hall said

OK that rules out interference from other programs on computer. Please restart Thunderbird in Safe Mode. In Thunderbird Help > Restart with addons disabled.

The behaviour is the same - a couple of error messages that summary files for Inboxes are missing, and no address books present. The counts of total number of messages are now not present (which probably confirms my suspicion that they were being produced by the add-on/extension I mentioned).

Right click on any pop mail account in folder pane and select 'Settings'

then for each pop mail account please check the following: select 'Server Settings' on right side at bottom you should see 'Local directory:' Please check that each pop mail account is pointing to the correct pop mail account name.

• C:\Users\david\AppData\Roaming\Thunderbird\Profiles\profile name\Mail\pop mail account

Use 'Browse' button to make sure each one is correct. clickon OK when finished.

Did you create the 'Sent Items' folder ? Hopefully the answer is Yes :) Do you see all three pop mail accounts listed in the Folder pane ? OR do you have all three POP mail accounts set up as Global Inbox, so all emails from all three email addresses go into 'Local Folders' Inbox ?

Toad-Hall said

Right click on any pop mail account in folder pane and select 'Settings' then for each pop mail account please check the following: select 'Server Settings' on right side at bottom you should see 'Local directory:' Please check that each pop mail account is pointing to the correct pop mail account name.

• C:\Users\david\AppData\Roaming\Thunderbird\Profiles\profile name\Mail\pop mail account

Use 'Browse' button to make sure each one is correct. clickon OK when finished. Did you create the 'Sent Items' folder ? Hopefully the answer is Yes :) Do you see all three pop mail accounts listed in the Folder pane ? OR do you have all three POP mail accounts set up as Global Inbox, so all emails from all three email addresses go into 'Local Folders' Inbox ?

Nothing has changed in my set-up between everything working and the current state (apart from creating extra local folders or sub-folders and filing Mail items into them). As I said earlier, this set-up has been working for several years ...

However, I have checked the "Local directores" as you asked and they all point to the correct places (if they didn't, then I'd not see the emails when I select that Inbox in the folders pane, which I do, and the Inbox.msf file would not be created, which it is).

"Sent" folders are all present.

There are more than 3 POP3 accounts - they are all set-up to show in the folders pane (i.e. they are NOT set to be Global Inbox). It appears that usually (though I'm not sure always) the "unable to open summary file" occurs for only two of the Inboxes (and it is the same two Inboxes).

Having come across this thread in the Mozilla Thunderbird bugs (https://bugzilla.mozilla.org/show_bug.cgi?id=495911), I moved the panacea.dat file out of the profile directory and let Thunderbird re-create it. I also deleted a number of newsgroup accounts that I was no longer using.

One of those actions has fixed the problem - Thunderbird is (at the moment) opening without any error messages relating to "unable to open summary file", my address books are present again, and I have total message counts for all folders.

The new panacea.dat file is only 260 KB whereas the old one was 783 KB.

Now I just need to move back the various files I moved out of the Mail directory early in this process (when I was thought the problem was related to file sizes) and see if that breaks Thunderbird again.