I can observe the same thing: opening a PDF attachment from the compose window will open it in firefox (or whatever application is configured for it), but opening the same attachment from the message after it's been sent opens it in a new tab in thunderbird.
That looks like an upstream problem, and from a cursory search I didn't find an existing bug for it. Would you mind filing one at https://bugzilla.mozilla.org/enter_bug.cgi#h=dupes%7CThunderbird and sharing the link to it here? Thanks! ** Changed in: thunderbird (Ubuntu) Status: Incomplete => Confirmed ** Summary changed: - Can't view attachment after attaching + PDF attachment is opened in Firefox from the compose window ** Summary changed: - PDF attachment is opened in Firefox from the compose window + PDF attachment opens in Firefox instead of the built-in viewer when opened from the compose window -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1945741 Title: PDF attachment opens in Firefox instead of the built-in viewer when opened from the compose window To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/thunderbird/+bug/1945741/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
