Multipart/alternative
I am receiving messages which Thunderbird is showing as blank where another email client shows the correct content. Looking at the source of the messages this is partly the fault of the sender as the message is sent as multipart/alternative and the first part is plain text us-ascii with no content, while the second alternative is multipart/related with html and several images. So Thunderbird would be valid to display nothing if it didn't support HTML. The RFC says "Either the user should be shown the last recognized version or should be given the choice.". There appears to be no way to tell that there are alternative views to see, or to change which one is shown. However I think this is also a recent change in Thunderbird. I don't recall noticing it before but looking back over messages from the same source for some time they all show the same issue.
Keazen oplossing
Turning it on had no effect, but in the same part of the options there were options for preferring plaintext (set to true) and how to display HTML (set to 1). This reinforced my view that there was a setting somewhere that controlled these, so I had another look in general settings and account settings and still could not find them. Eventually I did find them - the problem was that while they are application settings they aren't shown in the application settings. The only way to change them is via a menu item in the hidden menu (=|view|message body as|...).
There are number of issues with this. First: this is an application setting, so I can't just change it to view a problem message. Second: there is no indication on a message that there are alternatives. Third: there is no way to set it to message view - the order of the alternative parts indicates a preference set by the sender.
What I would like to see is a "view as" button or menu item on the message
Dit antwurd yn kontekst lêze 👍 0Alle antwurden (5)
These bug look like they cover this ground. https://bugzilla.mozilla.org/show_bug.cgi?id=568574 https://bugzilla.mozilla.org/show_bug.cgi?id=101719
and the grandaddy tracker of multipart/alternative bugs. https://bugzilla.mozilla.org/show_bug.cgi?id=505172
None of them quite match. In my case the message structure is correct and the alternate parts are in the correct order - plain then html. The issue is it is showing the first alternate not the second. Looking more closely this isn't just for these messages but for all messages, it is just that for these messages the first part contains a noticeably incomplete message. In one of those issues it implies there is a way to view the different alternatives however before reporting the issue I had looked for a way to select the part, both on the message, and in settings, and could not find anything. I had another look through settings when I realised that all messages were displaying the plain text part.
have you enabled the view all body parts discussing in the support document. https://support.mozilla.org/en-US/kb/configuration-options-attachments
Keazen oplossing
Turning it on had no effect, but in the same part of the options there were options for preferring plaintext (set to true) and how to display HTML (set to 1). This reinforced my view that there was a setting somewhere that controlled these, so I had another look in general settings and account settings and still could not find them. Eventually I did find them - the problem was that while they are application settings they aren't shown in the application settings. The only way to change them is via a menu item in the hidden menu (=|view|message body as|...).
There are number of issues with this. First: this is an application setting, so I can't just change it to view a problem message. Second: there is no indication on a message that there are alternatives. Third: there is no way to set it to message view - the order of the alternative parts indicates a preference set by the sender.
What I would like to see is a "view as" button or menu item on the message
You are welcome to file an enhancement request. https://bugzilla.mozilla.org/