there is not enough space in the hard disk

Have you checked your free disk space?

Yes... 205 GB of free space

Have you tried disabling your anti virus from scanning the profile that contains the mbox files? quite possible there is two programs playing there together and making a right royal mess of file permissions.

Than you, Matt.

I disabled both auto-protect and e-mail scanning options in norton (latest version). Then I restarted thunderbird, tried compacting and the same problem appears. I am not sure whether this would discard norton as the source of problem.

To diagnose problems with Thunderbird, try the following. Pticulaly the Operating system safe mode. Norton can bwe particularly recelcetrant in stopping. It will at times even lie about it's status.

• Restart Thunderbird with add-ons disabled (Thunderbird Safe Mode). On the Help menu, click on "Restart with Add-ons Disabled". If Thunderbird works like normal, there is an Add-on or Theme interfering with normal operations. You will need to re-enable add-ons one at a time until you locate the offender.
• Restart the operating system in safe mode with Networking. This loads only the very basics needed to start your computer while enabling an Internet connection. Click on your operating system for instructions on how to start in safe mode: Windows 8, Windows 7, Windows Vista, Windows XP, OSX

If safe mode for the operating system fixes the issue, there's other software in your computer that's causing problems. Possibilities include but not limited to: AV scanning, virus/malware, background downloads such as program updates.

Thank you, Matt.

I tried thunderbird's safe mode but the problem persists.

Then I tried safe mode in win10 and, also on that safe session, I started thundebird in safe mode. The problem is still there. Too annoying.

Compacting always stops working at a specific folder in two of my imap accounts (two different folders). I tried repairing these folders with the in-build option but that doesn't work either. I also tried setting a large space of cache space but... you know the rest :)

Thank you for trying.

PS: I have several plugins: google update, java platform,schockwave, photo gallery, m.office, which I can switch on and off but do not have any option for unistalling. Java deployment plugin is not activated for <<security reasons>> but I still cannot uninstall it.

You can try the 'real' fix, i.e. moving messages from the troubled folder to somewhere else. http://kb.mozillazine.org/Compacting_folders#Real_fix

Thank you, Christ.

I will need to have a "safe period" to try a real fix, just in case I break something. But, for now, it seems the only solution. I have no e-mails in the inbox, since I always reallocate them as they come. I hope this makes the process easier.

Thanks (thank you all)

It's always a good idea to create a backup before starting to mess with the profile. http://kb.mozillazine.org/Thunderbird_:_FAQs_:_Backing_Up_and_Restoring

Yes, that's right. I use Mozbackup... for now, it is still working. Thank you

Today I tried the "real fix" but the problem persists.

The compacting stops at the same folders and warns about space issues in my hard disk which is clean of viruses, malware and has a lot of empty space. I told the antivirus to stop messing with the inboxes and also restarted TB in safe mode...

I am trying to consider reinstalling TB... who knows...

thank you

@Christ1 @Matt What happens on the server-side when compacting an IMAP-folder?

@Christ1 @Matt What happens on the server-side when compacting an IMAP-folder?

Not a great deal really. Although the IMAP server will expunge deleted mail in a sync process. In a very similar way to Thunderbird clearing out the dead wood in the compact process. From the user perspective changing the Account option in server settings to mark as deleted provides a visual of this as deleted mail appears with a strike through until it is expunged on the server.

Moving the mbox file and MSF to the desktop should cause the folder to be completely recreated on restart and the sync mail in it.

However, perhaps it might be worth checking the server of use of IMAP Quota. Perhaps the issue is not enough space on the sever, not the local disk. A screen shot of the actual message might help.

When you right click the folder and select properties, what is the size on disk. Does your hard disk have twice the amount of space the folder consumes free?

Sorry for the delay.

1. Data: my main C:\ HDD where TB is installed is now 196 GB of 465GB of free space. My profile file in AppData > Roaming is 289 MB (could that be a problem? ups)

2. Snapshot attached below with error message when compacting.

3. Both my IMAP accounts have at least 40% of free space (one of them is a gmail account with much more free space and it still has the same problem to compact). The compact error appeared in all my imap accounts at the same time, which makes me think that the problem might not be the quota on the server (I don't know)

4. When I right-click on a folder that has problem to compact the size of it in HDD is max. 30 MB. Is that what you meant?

Thank you

Could be this bug. https://bugzilla.mozilla.org/show_bug.cgi?id=1174485

Good catch christ1

Thank you, Christ1.

That seems exactly my problem.

If this is eventually a bug, let's hope it is dealt with soon... I am not very familiar with the bug reporting-fixing on bugzilla

Thank you for taking time to write on this thread

Could you try this: Go into 'Offline' mode and then do the compacting. then when compacting is completed, go back to 'online' mode. what happens?

I click on Tools > Settings > Advanced > offline... There I choose an option "Manual status on bootup" > offline (approximate translation from Spanish) but compacting also fails after this.

If I restart TB with the above set to offline, then compacting is in grey and cannot be chosen.

Not quite sure that I'm doing what you recommended...

Start in normal online mode.

Q: Do you synchronise your subscribed folders?

What do you have here: 'Tools' > 'Account Settings' > 'Synchronization & Storage' for imap mail account or right click on mail account in Folder pane and select 'Settings' then select 'Synchronization & Storage' for imap mail account

Are these options selected ? ' keep messages for this account on computer' 'synchronise all messages locally regardless of age'

click on OK