Please try the following Steps.

• Open Thunderbird
• Left corner, Local Folder
  • Right click the Local Folder
    • Create New Folder under the Local Folder.

Now go to your email, Make sure your connected to internet. Choose the mail which you want to archive, Right click - Choose Move to scroll down the bottom in that option and you can see the Local Folder which you creates, Choose that one to move your mails to local archive.

Hello, this is not enough to solve the solution.

I rebuilt the Global Database. I have an IMAP folder where I have 5700 mails. I select the 100 oldest: - I choose Archive => nothing happens, - I choose move to Local... => nothing happens - I choose copy to Local... => nothing happens

Nothing happens = - no message in the "activity" window, - nothing arrives in the destination folder, - nothing disappear from source folder...

Provider is French Laposte.net

I try to move forward with experiments.

So I have disabled the synchronization of the files on the local PC.

I asked to "repair" one of the subfolders. It emptied everything in the subfolder and then downloaded all messages headers. Seems OK.

But when I click on the messages, I can't see the content of the message. Neither for the oldest ones, nor for the recent ones. I just get a blank page.

The subfolder is 5700 messages. On the webmail I can access to all messages content (still there and with something in).

What could I do wrong ?

JMF

have you disable you email scanner? It can be a huge cause of corruption and incomplete changes.

You should also create an exception in the anti virus product for the Thunderbird profile folder. Nothing like trying to write 5000 updates to a file that the anti virus has locked after the first one to scan it.

Next set Thunderbird to only mark deleted items as such in server settings for the account. Then it may be you will not see the disappear reappear thing happening.

Knowing the mail provider is often helpful in these cases. GMail, Yahoo and outlook all have peculiarities that can make achieving a mess.

Thanks Matt for your answer.

I use Windows10 with included anti virus (no additional third party product). My understanding is that I don't have a mail scanner.

I have set the exception on my Thunderbird profile folder. let's see if it helps.

I have set Thunderbird to only mark deleted items as such in server settings for the account.

My mail provider is laposte.net.

Currently, Thunderbird seems to be downloading the messages (so more than headers) for the folder, but at a super slow pace: 1 mail every 10s... and there are 4900 remaining. Don't know if it is an issue on the provider side or on my side.

JMF

Windows 10 anti-virys scans all documents that are downloaded. Emails are documents.

You would need to switch off this scanning whilst emails are downloaded. https://support.microsoft.com/en-gb/help/4027187/windows-10-turn-off-antivirus-protection-windows-security

Suggest you wait until download of current batch has completed so you do not interupt the process. Then switch it off.

Humm... It seems tha switching off the anti-virus helps having a much more deterministic behaviour.

One of the big folders is now resynchronized. I try on a second one.

I will then try to archive big part of those folders.

In the couse of the experiments, I have created a brand new profile. However I had started to archive in another profile, il focal folders. So I have already the beginning of the tree of 2010, 2011, 2012... folders, with subfolders.

Can I just move the corresonding files in the new profile (Archives.sbd, Archives, Archives.msf) inside the new profile and rebuild the global database ?

A better way to do it ?

Best regards,

JMF

re :Can I just move the corresonding files in the new profile (Archives.sbd, Archives, Archives.msf) inside the new profile and rebuild the global database ?

You can copy and paste files within 'Local Folders' into another profile 'Local Folders' or copy and paste the entire 'Local Folders' mail account. However, this must be done via the profile folders and Thunderbird must not be running. So Exit Thunderbird first, then access the profile and copy paste the ...\Mail\'Local Folders' folder from one profile into the other over writing the original 'Local Folders' folder or if you already have other emails stored in either Local Folders, then only copy all the 'Archives' (Archives.sbd, Archives, Archives.msf) and paste into new profile 'Local Folders' folder.

If you want to force a complete new rebuild of a global database, you can safely delete this profile file: global-messages-db.sqlite When thunderbird restarts a new file is created and repopulated.

This is really strange. TB keeps downloading the messages from the same folders again and again (which takes more than 1 hour).

In the activity pop-up window I have some message that the profile is up to date... and then if I click in one of the problematic folder... it restarts downloading all messages from #1.

I try to keep the anti-virus disabled (it had re-enabled on its own).

Don't know it it provides valuable information or not. For the big folder that is now OK, I remember that while downloading messages, in the Activity window, I had messages in parallel about indexing. For the folder I have difficulties at the moment, I don't see such messages about indexing.

JMF

By the way, I have also rebuilt the global database. JMF

More info to help understand what could be wrong. I have a "CNB" folder in the IMAP account. It just downloaded painfully the 4974 messages (about 90 minutes), and in ...\AppData\Roaming\Thunderbird\Profiles\...\ImapMail\imap.laposte.net

- the CNB.msf is of today, time about the time where the download started, - the CNB mbox file is still from the 19/11 (date of gthe creation of the profile), and is only abot 1000 Ko (far too small for the size of the folder)...

The activity window states that the profile is uptodate and that 10500 messages were downloaded (there are 2 problematic folders, and combined size is about that number).

Help ;-)

JMF

Exit Thunderbird. Open the explorer window to see profile info to see if it updated. If CNB mbox file now looks a better size all should be downloaded.

Start Thunderbird. If CNb file still looks too small.... Check to see if you have only downloaded headers.

• Right click on imap mail account name and select 'Settings'
• select 'Synchronisation & storage'
• Is the checkbox for 'keep messages in all folders for this account on this computer' selected?
• click on 'Advanced' button
• Is the CNB folder checkbox selected to download ?

If yes:

• Check to see if you can read the content of emails in the CNB folder.
• Go into offline mode.
• File > Offline > Offline
• If you can read the content of emails then you have good copies downloaded. This may take you a while to check.

If no:

• select CNB folder checkbox to download You may need to download again.
• click on ok
• click on Ok

Make sure the AV is switched off for a decent amount of time before attempting fresh download if required.

So still not completely solved... 2 out of 3 folders are OK, but the third one is reluctant to set itself correctly.

Disabling the Anti-Virus is a key to have a chance, but does not looks sufficient :-(

Something frustrating for me is that Thunderbird can download messages for 1.5 hours without spilling an error message, and that at the end, only a fraction of the messages are possible to read.

During the download process, either the .msf or the mbox file, or both get stuck: file size does not move anymore... but TB continue to download message after message, painfully, up to the end.

I believe that I have dowloaded that folder 5 to 8 times... without getting it correct at the end.

Sometime I had a big mbox, Sometime I had a correct msf size.

I have not found a way to keep what was good and build on it. The "repair" function from the folders seems to erase everything and redownload from scratch.

Even the sequence between the download of headers and messages looks not deterministic. Sometimes header first, then messages, sometime interleaved.

I love Thunderbird, but I have tough time here.

PS: yes folders are synchronized in the account parameters.

JMF

OK, succeeded to get the third folder (960Mo). So everything is onboard.

I will do a backup. Then tme to archive the messages.

What would be the safest to do it: - Online ? - Offline ?

Any other setting that would increase success chances (out of set Thunderbird to only mark deleted items as such in server settings for the account) ?

Thanks for all the help provided,

JMF

As you now have emails in mbox files, I would backup the entire 'Thunderbird' folder which means everything gets backup including address books, filters, etc etc.

To do backup: Exit Thunderbird.

Access profile: C:\Users\<Windows user name>\AppData\Roaming\Thunderbird Copy the 'Thunderbird' folder to an external hardrive of suitable size or other backup facility, but suggest not on same hardrive.

Start Thunderbird.

After you have gone through all the archiving and sorting etc, I would create another backup.

Done the first part as above. I start with clean situation, with " fresh synch" to the local PC. Antivirus disabled.

I have copied the mbox and .msf files in the local files.

Now would only need to delete the emails on the IMAP server.

I go the the older emails, select 100 and click delete. They are tagged as deleted (red cross)... and then they suddenly revert to not deleted, and messages are redownloaded :-(

Try to do it off line. Looks good. but when I reconnect, the messages are redownloaded

Try to compact folder fast... seems that some files are deleted, but not all.

Try to set the server to "delete immediatly" => same.

Only way seems to select only a small number of files, delete and compact immediatly.

TB and laposte.net does not seem to understand each others when it comes to deleting lot of old mails :-(

JMF