Web page triggered by clicking on email subject in the list pane
Recently, I have experienced an erroneous browser launch, simply by clicking on the title of the message in the list pane. This problem seems to occur when clicking on emails from a particular UK supermarket (tesco.com) and the web page opened has a long and complicated URL, but the page contains only a single pixel which shows up as a white dot on a black background.
Obviously, it is likely that there is something strange about that source, but the problem doesn't occur if I click on the same email in a different email client (in this case Evolution).
I have tried various Settings as advised by web searches and also the solutions suggested in Thunderbird Help (Troubleshooting Mode and Troubleshooting Information).
I am running Thunderbird 140.5.0esr (64-bit) on Kubuntu Linux 24.04.
Wšykne wótegrona (7)
No one wants to have a go here. I don't want to either really. But what you are seeing is what is talled a web bug. It is a single pixel image used by commercial mailers to track your activities in the email when and where is is read being the most ovvious but also how many times you open it as it is fetched everytime you look at the email.
Why it is opening in your browser can at this point only be conjecture. But I am guessing it may be like the old twitter icons and been included in the message as a remote image, but the link is to a script that serves the image, not to the image. Thunderbird does not accept output from scripts so the browser open to get the image. You might want to consider blocking remote images.
A script can grab a whole lot more fingerprinting information that simply serving an image so there are privacy implications for these things
Wót Matt změnjony
Matt said
No one wants to have a go here. I don't want to either really.
I'm not sure why 'no one want to have a go'. Is this something I should be ashamed of? As mentioned in the original query, the source of these problem messages is a major UK supermarket (probably the biggest), and I have been receiving these messages from them for years, without any problems until recently. Some are 'Special Offers', but most of them are information about forthcoming deliveries.
But what you are seeing is what is talled a web bug. It is a single pixel image used by commercial mailers to track your activities in the email when and where is is read being the most ovvious but also how many times you open it as it is fetched everytime you look at the email. Why it is opening in your browser can at this point only be conjecture. But I am guessing it may be like the old twitter icons and been included in the message as a remote image, but the link is to a script that serves the image, not to the image. Thunderbird does not accept output from scripts so the browser open to get the image. You might want to consider blocking remote images.
OK. If I understand this correctly, Tesco are monitoring what and when I read these messages; I don't really have a problem with that, but the implication is that Thunderbird is not handling these scripts correctly, especially since I don't have the same problem if I use a different mail client.
I have tried clicking on messages sent to me some time ago and the problem occurs with them too. However, I have only noticed this problem recently (within the last week or two), so I would say that something must have changed in Thunderbird since then.
Sounds to me like an RSS feed, which will show links in the title.
But ultimately I think we need a screen shot.
I'm not sure how a screenshot will help, since the shot of the list pane will only show a boring list of message subject lines and the shot of the browser will only show a black screen with a white spot in the centre. The real action is not shottable, since it only takes a few milliseconds or so.
I tried to record the screen, but this site does not accept the format (and the output is tens of MB.
The titles so not show anything RSS-like; eg, You've made changes to your tesco.com order 5501-8751-56, which generates a page https://click.mail.tesco.com/CI0/0102019b5a07d454-4d19a69c-a773-4435-9862-49dff481c756-000000/qSfHsgYKqs2JPKxnf5PtdyZ0ZHiqiTty2YyIDuo-aEU=437.
re :simply by clicking on the title of the message in the list pane.
If you hover mouse - not click - over the subject in Message List, do you see any link details shown in the bottom Status Bar ?
If you right click on email in Message list and select open in a new tab - does this trigger the browser ?
Do you have any allowed remote content in the following location?
- Settings > Privacy & Security
- Under 'Mail Content'
- Is this checkbox selected: 'Allow remote content in messages' ?
Advise is to not select that checkbox.
- Click on 'Exceptions' button
- Is there anything listed ?
Clear items in list.
Toad-Hall said
If you hover mouse - not click - over the subject in Message List, do you see any link details shown in the bottom Status Bar ?
No.
If you right click on email in Message list and select open in a new tab - does this trigger the browser ?
Yes. In fact, that action triggers two identical erroneous pages.
Do you have any allowed remote content in the following location?No.
- Settings > Privacy & Security
- Under 'Mail Content'
- Is this checkbox selected: 'Allow remote content in messages' ?
- Click on 'Exceptions' button
- Is there anything listed ?
No.
Musyśo se pla swójogo konta pśizjawiś, aby na pśinoski wótegronił. Pšosym stajśo pšašanje, jolic hyšći njamaśo wužywaŕske konto.