Thunderbird problems: “building summary file for Inbox”
Mozilla Thunderbird has trouble downloading new mail. The status bar shows “building summary file for Inbox”. Subsequent attempts to download mail may result in new messages being downloaded that are empty when you try to read them, multiple entries for new messages in the Inbox, or large numbers of reported unread messages that cannot be found. The symptoms may suggest a corrupt Inbox.
Solution
These problems can occur if you do not compact the Inbox. Mozilla Thunderbird mailboxes require periodic maintenance to prevent such problems from occurring. By the time the problems occur, compacting the Inbox, though still required, may not be sufficient to resolve the problem.
Method 1
Compact the Inbox if you have not already done so. Right-click the Inbox and select Compact this folder.
- Close Mozilla Thunderbird.
- Using Windows Explorer, navigate to the folder containing the messages for this account. This will be in a location similar to: C:\Documents and Settings\\Application Data\Thunderbird\Profiles\xxxxxx.default\Mail\. If you have multiple accounts on the same mail server then you may need to look at the names of the subfolders to identify which folder belongs to which account.
- Delete the file named Inbox.msf. (Do not delete the file named Inbox, with no file type extension. This is the file containing your messages, and it will probably be very large.)
- Restart Mozilla Thunderbird.
If the problem has not been resolved, try Method 2.
Method 2
Recreate the problem account.
- Select the problem account and click View settings for this account.
- Change the name of the account to e.g. Old .
- Select Server Settings, and clear all the options that check for or download new messages.
- Click Add Account, then create a new account with the same settings as the old one.
- Select all the messages in the Inbox of the old account and drag and drop them into the Inbox of the new one.
- Drag and drop any message folders from the old account to the new one.
- Manually recreate any message filters that existed in the old account.
- Once you are sure that all your messages have been transferred to the recreated account, delete the old one.
If necessary, you can use the Folderpane Tools extension to change the order of your Thunderbird accounts so that the recreated account appears in the same position as the original.
Compacting the Inbox
To ensure that this problem does not occur, you should configure Thunderbird to automatically compact mail folders. Click on Tools, Options, select Offline & Disc Space, and check Compact folders when it will save over xxxx KB.
Applies to
- Mozilla Thunderbird 1.0 and up
