Overview: Mozilla Thunderbird is a popular free and open-source email client which runs on Windows, macOS, and Linux. Its multiple account support also accommodates add-ons for sending and improving email business communications. But a problem that many of us experience is that although the emails are visible inside the Message folders, but Thunderbird not displaying message content problem occurs.

In case you can see the subject lines but not the body of the message is blank or incomplete, this is related to the Thunderbird configuration, add-ons, or damaged mailbox files. We will discuss the sources of this problem, the manual fixes, their limitations and finally the best practice to avoid this happening again.

Also Read: ImportExportTools Add-on For Thunderbird

Why Thunderbird Not Displaying Message Content? Key Reasons

The following are possible reasons why Thunderbird might not display the message body:

• Thunderbird creates .msf index files which track email. These objects become corrupt, then the message body will not be displayed.

• There might also be some add-ons or themes that interfere with message display.

• Some antivirus software will prevent Thunderbird from loading remote content, such as remote images in an HTML message.

• Incorrect IMAP/POP or Sync settings may also hinder Thunderbird from downloading or showing whole message bodies.

• The use of an outdated Thunderbird is also likely to create problems with modern mail servers and mail protocols.

• Large or corrupted MBOX files can cause Thunderbird to stop loading the body of certain emails.

• For security reasons, Thunderbird blocks remote content, including remote images, by default. So, this may be why you're seeing missing content.

Manual Methods to Fix Thunderbird Not Displaying Message Content

Here are the solutions you can try one by one to fix this Thunderbird issue.

1. Rebuild the Index .msf File

• Firstly, right-click on the folder like your inbox, sent, etc.

• select Properties.

• Click Repair Folder.

• Reboot Thunderbird and see if the message body is now showing.

This will make Thunderbird rebuild the.msf file and many times that will solve your problem with missing content.

2. Disable Faulty Add-ons and Themes

1. Navigate to Tools > Add-ons and Themes.

2. Disable any new or suspicious extensions.

3. Try to start up Thunderbird in Safe Mode (Help > Restart with Add-ons Disabled).

4. Once the issue is solved, delete the offending add-on for good.

3. Check Account Synchronization Settings

• Click on Tools > Account Settings.

• In the Synchronization & Storage area, make sure ``Keep messages for this account on this computer'' has been selected.

• Make sure to enable offline synchronization for any IMAP accounts.

• Restart Thunderbird Test by opening an email.

4. Allow Remote Content

• Open an email with no contents.

• At the top of the message pane, you’ll notice a line that says: “To protect your privacy, Thunderbird has blocked remote content in this message.”

• Click Options > Show Remote Content in This Message.

• Or you may whitelist known senders (Preferences > Privacy & Security > Remote Content).

5. Temporarily Disable Antivirus

• Try disabling antivirus/firewall, see if content loads.

• If there is, add Thunderbird to its exception list.

6. Update Thunderbird

• Click open Help > About Thunderbird.

• If there is an available update, download and install the update.

• Close and reopen Thunderbird and retest the emails.

7. Compact and Repair Mailbox Folders

• In Thunderbird navigate to: File > Compact Folders.

• This will somewhat clean up and small corruptions during sync.

• For problems that won't go away, fix the database manually by deleting the .msf file of the problem directory, and then restarting Thunderbird.

8. Reconfigure the Account 

• If you want to unspam within Thunderbird, then in Thunderbird, delete the offending account.

• Re-add it with proper IMAP/POP address details from your email provider.

• Re-sync emails to get full messages back.

Limitations of Manual Fixes

Although above methods are effective in many cases, they also have some drawbacks:

• Removing or fixing folders will cause loss of local stored emails if not backed up.

• Otherwise a rebuild of large mailboxes can take forever.

• Corruption can come back even after repairs if the size of the mailbox becomes too excessive.

• Some of the methods also involve going to profile directories that non-technical individuals may find difficult to understand.

• If the issue is caused by an antivirus or server-side issue, the fixes in Thunderbird do not necessarily solve the problem.

Thunderbird Not Displaying Message Content -  Alternative Way

Even after you have implemented all the manual workarounds and your Thunderbird not displaying message content, this could be happening due to invalid or inaccessible MBOX files. When your email becomes corrupted as a result of these issues, you may not be able to repair it using manual techniques.

SysTools Thunderbird Import Wizard is a professional software which allows you to easily import MBOX to Thunderbird within a few easy steps without losing any details. Using this method is a way to avoid the limitations of manual methods and makes sure all your email data is displayed correctly in Thunderbird.

Conclusion

When Thunderbird doesn’t show message content, we can become quite disturbed because it may halt our work. It often results from corrupt index files, unhealthy add-ons, or sync errors. The issue can often be fixed with manual methods like repairing the folders, upgrading Thunderbird, disabling add-ons or modifying account settings.

Always make a copy of your Thunderbird profile before attempting repairs. So that you can easily restore your profile from the backup in case something goes wrong. Even after the above steps, you are unable to fix the issue, fix the mailbox issue using our professional solution, or create a new Thunderbird profile.