Repair Corrupt Thunderbird Attachments and Reset Password of MBOX File

Thunder-bird is the most popular and widely used MBOX based email application. It is used by large number of individuals over the web-based application. Thunder-bird experience attachment error due to various reasons. These errors can be solved by changing the method to download an attachment. Check out the steps to repair corrupt Thunderbird attachments

Causes of Thunderbird Attachment Error

The Thunderbird application is set to download the attachments as a whole by default and if some time there is no resources available to download it fully, the system starts to download the attachments in chunks. If all, the chunks are not downloaded then the Thunderbird attachment error occurs. To resolve the error, the system is force to download the attachments completely by force.

Fix Thunderbird Corrupt Attachment File

  • Open Thunderbird application and go to Tools
  • Click on Options and a new box will open

fix thunderbird attachment issue

  • Click on the advanced setting option and then ‘General’ tab
  • Select the option ‘Config Editor’

thunderbird config editor

  • The editor will open to make changes
  • In the Filter field click on ‘mail.imap.fetch_by_chunks’

attachment issue fix in thunderbird

  • The item that appears, right click on it and select ‘Toggle’
  • Again in the Filter field type ‘mail.server.default.fetch_by_chunks’
  • Right click on item that shows up and then select ‘Toggle’
  • The attachments issue will be resolved, however if it still shows the error than changes the settings in filter option
  • as mail.imap.mime_parts_on_demand to false value
  • Try to change the mail.server.default.parts_on_demand to false.

In this way you can fix the Thunderbird attachment issue. Most of the times, the user is restricted to make changes in Thunderbird due to stored passwords. So, if you use Thunderbird to store your passwords and recently changed the Office 365 email account password then change the stored password.

How to Change Thunderbird stored Password

  • Open the Thunderbird application
  • For Windows machine: Go to Tools and then Options
  • For Mac: Go to Firefox menu and click on preferences

fix thunderbird attachment issue

  • Click on the Security button and select the Password tab
  • Click on the Saved passwords button

change thunderbird attachment settings

  • Click on Show Passwords and you may be asked to enter the master password
  • The list of account will open click on ‘Show Passwords’ in the link

change thunderbird saved password

  • Click on Yes on the dialog box to show password
  • Check the IMAP and SMTP account password and then highlight them, click on Remove password

remove thunderbird password

  • Close all windows and then quit Thunderbird
  • Reopen the Thunderbird, now the thunderbird will check for incoming server, but as it is deleted it will prompt for new password
  • Enter the new password and checkmark ‘Use Password Manager to remember this password’ and then Press OK

change thunderbird outgoing password

  • When you try to send a mail you will be prompted to set outgoing password

So, by following method you can simply delete the Thunderbird stored password. Follow the above steps to fix the Thunderbird corrupt attachments and change password

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