bugzilla Reporter
	Description • 7 years ago

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:58.0) Gecko/20100101 Firefox/58.0
Build ID: 20180206200532

Steps to reproduce:

Compressed folders only


Actual results:

POP3: Compress folder duplicates mails

When we are prompted by Thunderbird to compress a network folder (mbox) or do this manually, mails are duplicated over and over again.
This happens in all folders such as Inbox, Outbox and Archive folders that have not been changed. 
With the add-on "Remove Duplicate Messages" we were now able to delete more than 50,000 duplicates in all folders. Thus approx. 13 GB were free again! Thunderbird duplicates the mails in spite of repairing the folder!

Does anyone have an explanation or a solution?
Is there an error in that we don't store the folders locally but on the network?

(I still hope that soon the storage method (maildir) will be released and the error disappears)


Expected results:

Compress only

	Wayne Mery (:wsmwk)
	Comment 1 • 7 years ago

1. Are you using a non-English build of Thunderbird?   I ask because the term used in English builds is "compact".

2. Specifically what flavor and version of network share are you using?  Please give as much detail as possible.

	bugzilla Reporter
	Comment 2 • 7 years ago

(In reply to Wayne Mery (:wsmwk) from comment #1)
> 1. Are you using a non-English build of Thunderbird?   I ask because the
> term used in English builds is "compact".

Yes, we use the German version (52.6.0 32-Bit) with no Active Add-Ons.

> 2. Specifically what flavor and version of network share are you using? 
> Please give as much detail as possible.

We use a Windows domain network. On the client PC is "Windows 10 Pro. 1709" and a server with "Windows Server 2008 R2".
The network drives are linked by a drive letter. In the "Account Settings", server settings under "Local Folder" the following is entered: "F:\E-Mail_Archiv\User". ("F:\" is the linked network drive).

Further information:
We've had this mistake for over a year now.
In the advanced settings, "Global search and message indexing" is disabled.
It is noticeable that the mails are only multiplied after compression. (After multiple compressing a mail exists for example 9 times)
Repairing a folder's summary file (*. msf) does not change anything. The mails are retained and can be deleted individually!

	bugzilla Reporter
	Comment 3 • 7 years ago

Has someone noticed the same problems (emails exist several times) in a local folder?

	Wayne Mery (:wsmwk)
	Comment 4 • 6 years ago

I have no specific reason to think it would be better, but can you try the beta from http://www.mozilla.org/en-US/thunderbird/channel/ ?

I'd bet this is related to the profile being on a file share.
* You are not using roaming, correct?  (i.e. Thunderbird is running directly off the file share)
* Does this happen with every single compact?

	bugzilla Reporter
	Comment 5 • 6 years ago

(In reply to Wayne Mery (:wsmwk) from comment #4)
> I have no specific reason to think it would be better, but can you try the
> beta from http://www.mozilla.org/en-US/thunderbird/channel/ ?
 
This is a good idea, as the experimental function for converting mbox to maildir is available.
I have been testing maildir on an account for some time and could not find any errors. Since each mail is then saved in its own file, I can finally let go the virus scanner on the mail folders to detect e.g. 0-Day-Virus afterwards.

> I'd bet this is related to the profile being on a file share.
> * You are not using roaming, correct?  (i.e. Thunderbird is running directly
> off the file share)
> * Does this happen with every single compact?

TB is installed locally and therefore also the profiles folder.
The mails are also not duplicated with each compress.
Currently I have just found two duplicate mails that have been manually moved to an archive folder with some subfolders in the last two months. I can't tell when this was last compressed, because in the settings the compression is set to more than 200 MB free memory. This delays the error a little.

	Wayne Mery (:wsmwk)
	Comment 6 • 6 years ago

(In reply to bugzilla from comment #5)
> (In reply to Wayne Mery (:wsmwk) from comment #4)
> > I have no specific reason to think it would be better, but can you try the
> > beta from http://www.mozilla.org/en-US/thunderbird/channel/ ?
>  
> This is a good idea, as the experimental function for converting mbox to
> maildir is available.
> I have been testing maildir on an account for some time and could not find
> any errors. Since each mail is then saved in its own file, I can finally let
> go the virus scanner on the mail folders to detect e.g. 0-Day-Virus
> afterwards.

If you are currently letting antivirus scan your thunderbird profile, then all bets are off.  Your AV software should not be scanning data by default, and if it is scanning you should set an exclusion.  

If you want AV to scan individual messages the approved method is tools > options > security > antivirus > allow AV clients to quarantine individual incoming messages


> > I'd bet this is related to the profile being on a file share.
> > * You are not using roaming, correct?  (i.e. Thunderbird is running directly
> > off the file share)
> > * Does this happen with every single compact?
> 
> TB is installed locally and therefore also the profiles folder.

Installing the program locally does not imply the profile data is local. But apparently you have changed one or more computers since comment 2, where you said profiles were on a network file share?

	bugzilla Reporter
	Comment 7 • 6 years ago

(In reply to Wayne Mery (:wsmwk) from comment #6)

> If you are currently letting antivirus scan your thunderbird profile, then
> all bets are off.  Your AV software should not be scanning data by default,
> and if it is scanning you should set an exclusion.  
> 
> If you want AV to scan individual messages the approved method is tools >
> options > security > antivirus > allow AV clients to quarantine individual
> incoming messages
>
> Installing the program locally does not imply the profile data is local. But
> apparently you have changed one or more computers since comment 2, where you
> said profiles were on a network file share?

The Setting "options > security > antivirus > allow AV clients to quarantine individual incoming messages" is on.
TB is installed on (Windows) "c:\programs..". (This folder is scanned by the AV scanner)
TB-Profile is on "c:\Users\xx\AppData\Roaming\Thunderbird\Profiles\xx.default\" (This folder is scanned by the AV scanner)
In the Account Settings > Server Settings > Local Folder the folder is "f:\E-Mail_Archiv\User" (This Sharedfolder is NOT scanned by the AV scanner)

Which of these folders should I not scan?

	Wayne Mery (:wsmwk)
	Comment 8 • 6 years ago

No folders in the profile should be scanned. So the exclusion should be on c:\Users\xx\AppData\Roaming\Thunderbird\Profiles\xx.default\