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Why are popstate-xx.dat email folders appearing?

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  • 3 have this problem
  • 14 views
  • Last reply by BillBlasic

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Running Thunderbird 52.5.2 (32 bit) on Windows10 (64 bit). About a week back (~Dec 27) email folders named popstate-nn.dat have started appearing on my folder list when I fire up the client. There are often more than 20 of these folders with nn in the folder name being 1 to >20. All the folders are empty. These are a pain in the rear to delete as there is apparently no way to do mass email folder deletions in TBird. How can I make TBird stop creating these folders?

Running Thunderbird 52.5.2 (32 bit) on Windows10 (64 bit). About a week back (~Dec 27) email folders named popstate-nn.dat have started appearing on my folder list when I fire up the client. There are often more than 20 of these folders with nn in the folder name being 1 to >20. All the folders are empty. These are a pain in the rear to delete as there is apparently no way to do mass email folder deletions in TBird. How can I make TBird stop creating these folders?

Chosen solution

The folders are created usually by a bad interaction between Thunderbird and an anti virus program or other program that is trying to use the files at the same time as Thunderbird.

My first guess is an anti virus program as there is no reason for any other program other than some sort of backup program to ever access Thunderbird configuration file to the point where there is access contention. I mention backups because there are a few misguided souls that try and place Thunderbirds profile folder in a location that syncs to google drive or one of the other cloud sync services. The results are rarely pretty.

When Thunderbird goes to get your mail from a pop mail server it refers to this popstate file as a memory of where things are up to. If the file is missing it is recreated. If it is simply locked either as read only (usually only occurs if files have been on CD or DVD) or by another process a new file is created. Because the new file has a number Thunderbird mistakes it and shows it as a folder in the user interface.

So I suggest you create an exception in your anti virus program for the Thunderbird profile folder.

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Seçilmiş Həll

The folders are created usually by a bad interaction between Thunderbird and an anti virus program or other program that is trying to use the files at the same time as Thunderbird.

My first guess is an anti virus program as there is no reason for any other program other than some sort of backup program to ever access Thunderbird configuration file to the point where there is access contention. I mention backups because there are a few misguided souls that try and place Thunderbirds profile folder in a location that syncs to google drive or one of the other cloud sync services. The results are rarely pretty.

When Thunderbird goes to get your mail from a pop mail server it refers to this popstate file as a memory of where things are up to. If the file is missing it is recreated. If it is simply locked either as read only (usually only occurs if files have been on CD or DVD) or by another process a new file is created. Because the new file has a number Thunderbird mistakes it and shows it as a folder in the user interface.

So I suggest you create an exception in your anti virus program for the Thunderbird profile folder.

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I should make clear that the problem here had nothing to do with virus, backup or any other SW accessing the TBird config tree. The problem was one of TBird and the POP server disagreeing about what email messages were new/read/deleted and which were not. Got that squared with the folks hosting my domain, and the offending folders stopped getting created.

Thanks for pointing the finger at the source of the issue.

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None of this works I erase them and they keep coming back in all 5 of my email addresses. I sometimes have over a hundred in each. And sometimes each one has a popstate-1.msf or something. Every day and they comeback during the day as I'm using the computer.

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Did you create an exception in your anti virus product of choice for the Thunderbird profile folders? That is the most common cause of what you say you are seeing.

That is followed by backup software. What I do know is statements like "None of this works" convey little or no information.

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The only thing I have is Windows Defender and that will not let me get to those files. When I tried making an exception for .dat files I just got more of the popstate files.