ooppsss... This is happening in version 45 of Thunderbird running on Windows 7 pro

Press F10 to make the top menu visible.

The only "rendering controls" are on the view menu. Messagebody as > Original HTML being the most common issue. There are no display per account settings, only compose per account settings

It is unlikely that a payload from an email is involved as scripting it not allowed in emails.

Now lets look at the emails. Ctrl+U. Is there actually HTML in the message source?

Does the same thing occur in safe mode. Restart with add-ons disabled from the help menu?

Thank you for your reply Sorry within HTML there is a certain amount of scripting that goes on behind the scenes... or it wouldn't render properly...

And yes, there is HTML content - can see the HTML in webmail... we had not tried to start in safe mode to try restart with add-ons disabled... But, if add-ons were a problem, it would probably effect both email accounts... this only affects the gmail account but not the other providers account (this account renders HTML messages perfectly).

We had another machine a few years ago that had an "bug" that only affected their company webmail account (added a payload to each email), but did not effect their personal email accounts using their email client - it was a real stinker to remove too... So we know that targeted "non-authorized" features show up with a certain amount of frequency...

HTML encoded messages generated in Thunderbird have ZERO scripting content. Scripting is NOT necessary to html. If by "behind the scenes" you mean "at the server", then well, maybe, but that's not relevant to an email client.

I'm with Matt. I don't know of any case where "payload" has affected Thunderbird in this way.

Errors in HTML rendering can be affected by content, and the structure of email messages. So I wouldn't rule out an add-on having an effect on specific accounts.

When investigating an issue with character encoding recently, I was surprised to find that a message that had been originated using UTF-8 arrived via a Gmail account in an ISO encoding. Now the message may not have involved any characters that required UTF and therefore all the text may have been expressible in an alternative and more compact encoding, but the fact that the message had been manipulated by the email provider does raise the possibility of provider-specific errors.

Please tell us the outcome of using Safe Mode.

Also, is this a vanilla Gmail account, or one of the corporate, owner-managed flavours? Might it be customised or tweaked in some unconventional way?

okay guys here is the latest... Was able to get to the client and her computer today...

1) ran Thunderbird in "safe mode" still blank screen... and then tried to load message with html content - still get message at bottom of screen "loading message" 2) ran the "eM Client" ver.7 at the same time on the same computer and it opens the same email just fine...

3) deleted (actually moved every instance & Thunderbird directory to a temporary directory) Thunderbird and tried to delete every instance of "preferences and settings" for Thunderbird on the computer... This included: Program Files (X86)/Thunderbird Users/USERS-NAME/appdata/local/thunderbird Users/USERS-NAME/AppData/roaming/Thunderbird

and then reloaded the program with exactly the same results... So, Thunderbird must have some other places and files that it uses that were missed in the reinstall...

Thats all their is for now...

jrazor said

Thank you for your reply Sorry within HTML there is a certain amount of scripting that goes on behind the scenes... or it wouldn't render properly...

Not in Thunderbird there is not. HTML is "sanitized" and no scripts are allowed to run locally. Remote scripts, such as the twitter logo actually opens a blank browser window. But it does not affect Thunderbird.

We see all sorts of issues occasionally with log files from routers and the like that rely on JavaScript that will not render due to the prohibition on scripts.

This does not apply to RSS feeds, scripting is allowed in that context, but still sanitized.

And yes, there is HTML content - can see the HTML in webmail...

Not relevant. I have seen local anti virus for instance completely mangle an email body or it's attachments that is does not even scan in web mail. So to look and see what is present one must look at the message source in Thunderbird.

we had not tried to start in safe mode to try restart with add-ons disabled... But, if add-ons were a problem, it would probably effect both email accounts... this only affects the gmail account but not the other providers account (this account renders HTML messages perfectly).

You may well be correct. But I have spent more time replying to you than it would take to confirm that surmise. I would guess it takes less than a minute to restart Thunderbird. Holding the shift key while that happens is hardly a burden.

I also suggest you provide a screen shot of exactly what you are seeing. After all what is rendering. I assume something is appearing in the display pane

Perhaps you could send me one of the emails that is not rendering. Right click it in the list and save as a file. Zip the file and send it to unicorn dot consulting at gmail dot com with a link back to here so I know what it is. Before doing that however you might want to forward one of the mails to the other account and see if it renders correctly when downloaded. That might narrow to area to either the structure of the email itself, or something else.

We had another machine a few years ago that had an "bug" that only affected their company webmail account (added a payload to each email), but did not effect their personal email accounts using their email client - it was a real stinker to remove too... So we know that targeted "non-authorized" features show up with a certain amount of frequency...

They appear usually in mail clients that allow scripting. Such products as those from Microsoft especially the Outlook and Outlook express lines have been prone to scripting issues for the last 15 years to varying degrees. One of the reasons email is such a broad vector in business as a security risk is the wide spread adoption of Microsoft mail clients.

About the only way a machine can contract malware using Thunderbird is from the user opening an attachment, and anti virus should scan ALL attachments before they are actually opened when Thunderbird places the file in the Temp folder for the operating system to open.

It is worth knowing that until Thunderbird creates the binary representation of the file in memory at the time you request it be opened/detached/saved. It does not exist on the system. Until then it is a harmless collection if mime encoded text in the body of the email. No more executable than something written on a piece of paper.