On 14/2/23 15:21, Tim via users wrote:
supplemental:
I should point out that I don't *use* Thunderbird. I have it installed (the one from Fedora's preinstallation, not a different "daily" one), and can experiment with it, but I use Evolution. Out of all the email clients I've tried on Linux, it's the least-worst. Not the best recommendation, but that's how things evolved (pun intended)
Hunting around, I managed to find an email with a misidentified PDF file attachment (as application/octet-stream). Though I couldn't find one with a blank space in the name.
Evolution will open it when clicked on, just the same as a correctly identified one (as application/pdf), in my PDF reader. Or, perhaps I should say that my system (Mate spin of F36) does, Evolution has no obvious mimetype configuration options.
I think Thunderbird is the same, I'm using KDE's application/pdf settings to specify Acrobat as the default. Every entry in Thunderbird's "Files & Attachments" table is set to "Always Prompt" (I don't remember whether this was a Thunderbird default or whether I changed them to that). Also, when clicking on an application/octet-stream pdf attachment, if I select other in the prompt, Acrobat does not appear in the list of applications that can be used to open the pdf. Interestingly, for both mimetypes, Chrome and Chromium both appear in the application list, Firefox doesn't because with the way it is installed I would have to add it manually if I wanted to.
Thunderbird will open it when clicked on, within itself. Likewise for correctly identified ones. I only get open, save-as, detach, delete options, no open-with options, on the message reader.
With the pdf options in Thunderbird set to "Always Prompt" I get a dialogue the shows "Open With", "Save File" and a check box "Do this automatically for files like this from now on.". The open with entry is a drop down list that contains "Adobe Reader 9 (default)", "Okular" and "Other". If I click on "Other" it displays a list of "Recommended Applications" which is all the application entries in the application/pdf mimetype list except for the snap installed Acrobat DC entry (it does this for both mimetypes even though the application/octet-stream list is empty in system settings, incidentally it has only done this for the application/octet-stream since installing the linux version of Acrobat Reader 9.5.5), and a button for "View All Applications" and a button for "Find New Applications". Interestingly, if having clicked on "Other" I then select "Cancel" it changes the displayed name in the drop down to "Okular" instead of "Adobe Reader 9 (default)" which was shown when the dialogue opened.
regards, Steve
If I go into the Thunderbird settings, and change PDF handling to an external reader, it works (correctly and incorrectly identified mimetyped files are opened externally).