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Message Pane (preview) shows email source code for wrong message
System specs below. Thunderbird is set with 1 account: A paid Yahoo email, with a LOT of messages (well over 36K), using IMAP (Yahoo only lets the most recent 10K come down via IMAP, sadly). Most emails do download and are correctly rendered. But around 10%, starting usually a month or so back from the high water mark of last update, show email source code (text of headers, mimeparts, etc.) for a totally different email than the one highlighted (a few days later, different sender, etc.) Checking the message on Yahoo, it renders correctly. There is no pattern to the corrupted messages: they can be from mailing lists, company marketing mails, an alert from my local town, whatever.
Once the error occurs, it is consistent across Thunderbird shut-and-restarts (still showing same wrong email source as before). Emails to either side (earlier and later) render properly in the message pane.
Double Clicking the message to it's own child pane renders a pane with Subject and From as blank, and the same email source text for a different email. Forwarding the email puts the email source code in as text (I was hoping the act of refreshing and reformatting might grab the correct content, but no).
Doing a Repair Mailbox (which seems to mean "download headers again, then download all the mail again" does seem to correct for a time (including the previously corrupted emails now rendering correctly)... but within a day or two, a new crop of messages will be corrupted, and the dance starts again.
Windows 10, 64 bit. Norton 360 set to exclude all mailbox directories. Thunderbird 115.12.2 (64-bit), though this has been happening since 110. No plugins, no extensions.
Are there diagnostic logs or other info I can share that can help us figure this out? I really like Thunderbird, but it's just unusable here. Outlook, Apple mail, other tools don't seem to have this problem.
All Replies (7)
Norton 360 set to exclude all mailbox directories.
What's the exact full path for these exclusions?
Anti-virus software is known to be causing Thunderbird mail file corruption, and Norton is no exception. These are some generic suggestions to avoid problems with anti-virus software.
Create an exception in your anti-virus software for the Thunderbird profile folder, so that the anti-virus real-time scanner will not scan it. https://support.mozilla.org/en-US/kb/profiles-where-thunderbird-stores-user-data#w_how-to-find-your-profile
Don't let your anti-virus software scan incoming and outgoing messages.
Don't let your anti-virus software scan attachments.
Don't let your anti-virus software intercept your secure connection to the server.
Remove any add-ons your anti-virus software may have installed in Thunderbird.
Keep it working. http://kb.mozillazine.org/Keep_it_working_-_Thunderbird
And last but not least, backup your Thunderbird profile on a regular basis. https://support.mozilla.org/kb/profiles-where-thunderbird-stores-user-data#w_backing-up-a-profile
Thank you for the post. When I setup Thunderbird, I moved my mailbox to a specific location (off my SSD and onto spinning disk), so D:\Thunderbird_Data\ has all the usual stuff (sqlite data, etc) with over 2 TB still free on the drive.
And this entire directory is set as Excluded from Scans and Excluded from Real Time "auto-protect" in the well hidden and difficult to access Scan Exclusion tab in Norton 360. Norton has not been configured for Thunderbird mail scan for virus or for spam. And Thunderbird no add-ons are present of any kind.
This (virus scan corruption) was the first thing I thought of, too. But it doesn't seem to be the issue.
An gyara
Can you verify your profile location and post the full path? See https://support.mozilla.org/en-US/kb/profiles-where-thunderbird-stores-user-data#w_how-do-i-find-my-profile
Via the three bar (hamburger) menu, Help > Troubleshooting Info: "open folder" opens the D:\Thunderbird_Data\Michael_Wexler directory. As I said, I moved all that stuff over to my spinning disk as it has more room than my SSD c: drive.
This (virus scan corruption) was the first thing I thought of, too. But it doesn't seem to be the issue.
The real-time scanner doesn't seem to be the issue. But do you still let Norton scan incoming and outgoing messages?
No, as I mentioned in previous post: Norton is not configured to scan the emails in any way, nor is any other tool. This includes both "file scan" from Norton as well as the "Safe Email" feature (which is POP3 only and so useless for modern IMAP connections).
I understand and appreciate that virus scans can cause corruption of the mail files, the msf indexes, etc. But if that were not the cause here, are there other things we can look at to diagnose? Log files which would reveal possible issues?
An gyara
Is there anything related in the Error Console (Ctrl-Shift-I)?
An gyara