Check Thunderbird for Updates: Ensure your Thunderbird is running the latest version, as bug fixes and performance improvements could help with issues like this. Updates often resolve underlying problems with the email display.
       Go to Help > About Thunderbird and make sure you’re running the latest stable version.

   Increase the Frequency of Folder Repair: While you can't fully automate this process (i.e., having it auto-repair every time the issue happens), you could set Thunderbird to automatically perform a folder repair in the background more frequently.
       Open Account Settings by clicking on Menu > Account Settings.
       Select your Account and click on Synchronization & Storage.
       Under Message Synchronizing, ensure you have Keep messages for this account on the server selected and choose the Download messages for offline use option as well (if applicable to your setup). This ensures your local data is frequently synchronized with the server.

   Compact Folders Regularly: The issue might also be related to Thunderbird needing to compact the folders to prevent corruption in the index files. You can enable Thunderbird to compact folders automatically:
       Go to Tools > Options (or Preferences on macOS) > General.
       Scroll down and click on Config Editor.
       In the search bar, type mail.compact and look for the setting mail.imap.autosync. Set this to true.
       This will allow Thunderbird to auto-compact folders when it’s not in active use, which can help prevent indexing issues.

   Check your Email Headers: The issue could be related to a problem with how Ziggo’s mail server is sending email headers. Sometimes, mail servers can send malformed headers that Thunderbird has trouble parsing, causing the missing sender name or subject.

   If this continues, it’s worth rechecking with your provider to see if they can ensure proper header formatting. If they can’t fix it on their end, consider using another mail server or an email forwarding service temporarily to see if that resolves the issue.

   Use the "Global Inbox" (for IMAP accounts): If you're using IMAP, you might want to switch to using Thunderbird’s Global Inbox. This is essentially a unified inbox for multiple accounts, and it can sometimes solve problems with mail synchronization and index issues.

   To switch:
       Go to Account Settings > Server Settings.
       Under Local Folders, select Global Inbox for each account. This helps Thunderbird handle mail indexing more smoothly.

   Try Using a Clean Profile: If Thunderbird's profile is starting to become corrupted, it can cause persistent issues with email rendering and behavior. You can create a new Thunderbird profile and move your existing emails to it:
       Close Thunderbird.
       Run Thunderbird’s Profile Manager by pressing Win + R, typing thunderbird.exe -P, and pressing Enter.
       Create a new profile and test whether the issue persists in the new profile.

   If the new profile doesn’t have the same issue, you can transfer your emails to the new profile.

   Use a Dedicated Email Client Repair Tool: Some third-party utilities are designed to scan and repair Thunderbird's profile and settings. If you’re comfortable with trying third-party tools, you can search for Thunderbird profile repair utilities that might automate or fix the problem permanently.

   Go to Bugzilla: https://bugzilla.mozilla.org/ and file a bug report about your issue.While there isn't an out-of-the-box solution to fully automate the folder repair process in Thunderbird, the steps above should help reduce the frequency of the issue and make it easier to manage. If the problem is indeed caused by a server-side issue, working with Ziggo (or a different mail provider) could potentially address the underlying issue.

hello Laurens!It sounds frustrating to have to go through that procedure every time you receive an email with these issues, especially when it’s recurring. The problem you're experiencing seems to be related to how Thunderbird is handling the folder indexes (and possibly email headers) for your inbox. Let's go through a few possible solutions and settings adjustments that might help automate or resolve this problem so you don’t have to manually repair the folder each time. Possible Solutions Check Thunderbird for Updates: Ensure your Thunderbird is running the latest version, as bug fixes and performance improvements could help with issues like this. Updates often resolve underlying problems with the email display. Go to Help > About Thunderbird and make sure you’re running the latest stable version. Increase the Frequency of Folder Repair: While you can't fully automate this process (i.e., having it auto-repair every time the issue happens), you could set Thunderbird to automatically perform a folder repair in the background more frequently. Open Account Settings by clicking on Menu > Account Settings. Select your Account and click on Synchronization & Storage. Under Message Synchronizing, ensure you have Keep messages for this account on the server selected and choose the Download messages for offline use option as well (if applicable to your setup). This ensures your local data is frequently synchronized with the server. Compact Folders Regularly: The issue might also be related to Thunderbird needing to compact the folders to prevent corruption in the index files. You can enable Thunderbird to compact folders automatically: Go to Tools > Options (or Preferences on macOS) > General. Scroll down and click on Config Editor. In the search bar, type mail.compact and look for the setting mail.imap.autosync. Set this to true. This will allow Thunderbird to auto-compact folders when it’s not in active use, which can help prevent indexing issues. Check your Email Headers: The issue could be related to a problem with how Ziggo’s mail server is sending email headers. Sometimes, mail servers can send malformed headers that Thunderbird has trouble parsing, causing the missing sender name or subject. If this continues, it’s worth rechecking with your provider to see if they can ensure proper header formatting. If they can’t fix it on their end, consider using another mail server or an email forwarding service temporarily to see if that resolves the issue. Use the "Global Inbox" (for IMAP accounts): If you're using IMAP, you might want to switch to using Thunderbird’s Global Inbox. This is essentially a unified inbox for multiple accounts, and it can sometimes solve problems with mail synchronization and index issues. To switch: Go to Account Settings > Server Settings. Under Local Folders, select Global Inbox for each account. This helps Thunderbird handle mail indexing more smoothly. Try Using a Clean Profile: If Thunderbird's profile is starting to become corrupted, it can cause persistent issues with email rendering and behavior. You can create a new Thunderbird profile and move your existing emails to it: Close Thunderbird. Run Thunderbird’s Profile Manager by pressing Win + R, typing thunderbird.exe -P, and pressing Enter. Create a new profile and test whether the issue persists in the new profile. If the new profile doesn’t have the same issue, you can transfer your emails to the new profile. Use a Dedicated Email Client Repair Tool: Some third-party utilities are designed to scan and repair Thunderbird's profile and settings. If you’re comfortable with trying third-party tools, you can search for Thunderbird profile repair utilities that might automate or fix the problem permanently. Consider Submitting Feedback to Mozilla: If the problem persists, you may want to consider reporting it directly to Mozilla. Sometimes ongoing issues like this may require developer attention to get properly addressed. To submit feedback or report bugs: Go to Bugzilla: https://bugzilla.mozilla.org/ and file a bug report about your issue.While there isn't an out-of-the-box solution to fully automate the folder repair process in Thunderbird, the steps above should help reduce the frequency of the issue and make it easier to manage. If the problem is indeed caused by a server-side issue, working with Ziggo (or a different mail provider) could potentially address the underlying issue. Let me know how these steps go, or if you need any more details on any specific step!with regards Sakura.