Corrupt mailbox in Thunderbird

CraigSNYC used Ask the Experts™
I have a client who uses the Thunderbird email client.  It appears that one of the mailboxes/email addresses is corrupt.  When he tries to read email in that mailbox Thunderbird crashes.  However, this doesn't happen with any of the other mailboxes/addresses.  

I think I'm going to delete the mailbox/address and re-add it but wanted to make sure the email currently there won't disappear.  And, is there a way to re-sync the old emails to the newly setup address.

From my reading about it it seems that that is possible since there are separate files for each mailbox/address.

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That seems like taking a sledgehammer approach. I'd suggest a scalpel.

Does reading the mail in any of the folders for a particular address cause the crash, or just a particular folder (like the Inbox)? If it's just one of the folders, you can focus on that.

Each folder in TB is a separate physical file on disk. Actually, there are two files: a file with the folder's name and no extension, which actually contains the messages, and a second file with the same name and an extension of .msf, which contains an index to the messages. You can find where the files are located in Tools/Account Settings, Server Settings for the account you're concerned with (see Local Directory). With TB closed, first make a complete backup of all files in that folder (I'd suggest creating a zip archive). Now delete the .msf file for the offending folder(s). Restart TB; it will automatically recreate the index. That may solve your problem.

If not, there's something corrupt in the mail file itself for that folder. Compacting the folder (available from the right-click context menu for that folder) may clean up the problem, or it might get messed up by the same problem. If you have only a few messages in the folder, you may be able to manually edit the file, but that is definitely trickier.


I *believe* it's when any of the folders for the particular address are opened.  I'm verifying that.  

I'm used to Outlook's .PST file which contains all data for all email addresses used in Outlook.  From my reading it appears that Thunderbird, wisely, has separate files for each address.  Correct?  
TB has a separate physical file for each folder within each address. Each address's mail folders/files is stored in a different Windows folder. (The terminology gets confusing, because "folder" means something different inside TB and at the Windows system level.)

If you're having a problem with all the mail folders for an address, I'd suggest deleting all the .msf files for that email address.
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FYI: It's only when the inbox is opened, not when the sent folder, etc. are opened.  

Still the same fix?
Yes, I'd suggest the fix in my first comment, looking at just that one folder. Close TB, make a copy of the Inbox file (the one with no extension in the name), delete the Inbox.msf file, reopen TB, and see if that fixes it. If not, right-click on Inbox and choose Compact. If that doesn't work, how big is the file (size in My Computer/Windows Explorer)?
In the absence of any further response from the poster, I would suggest deleting the question. There's no way to know if my suggestion will be successful.


Please forgive my tardiness in updating the question!!


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