Header errors in importing Thunderbird mail

With a newly installed DTP Office 2.0pb8 on Mac OS X 10.5.8, I am trying to import Mail from Thunderbird. It is in several accounts, with a 4-level deep folder hierarchy in one of the accounts. I couldn’t get DTP Office to recognize any mail folder, so I started to do it mailbox by mailbox (File>Import>Email… select “Inbox” and group by thread). There were over 22000 messages, most of them Junk (which Thunderbird had previously identified as Junk, so I don’t know why they were in “Inbox” in the first place).

I started to delete the “Junk” threads, but I had to look at some of them to determine whether they were junk. I noticed that some of them had more than one sender and subject line, so shouldn’t be part of the thread. But on looking at the actual messages, I found that many, but not all, of the odd messages actually did belong in the thread. I attach a screenshot of an example, showing a selected message that belongs in the thread called “Control” in the left column listing (not shown), though the displayed subject line is from a quite different message thread.

Is this a known problem that I should do something to fix, or have I simply done something silly? Or, is it a bug (I hope that’s not the answer).


The threading support is based on the old Netscape 3 algorithm which is still considered the best one by many.
There are so many different definitions of Junk flags that we can’t support them all since a lot of them seem to be mail client specific. And since we don’t have “rich” support for Thunderbird since it doesn’t have an AppleScript interface, we can only determine the Junk status based on the flags in the mail headers. If Thunderbirds keeps those in a separate database, we don’t have access to it.

My question isn’t really about junk filtering. It’s about why the top panel of a set organized by thread says a message has one subject and a given sender, when the actual message you see when you click on it has a different subject and sender. The actual message belongs in the thread, and the reported header and sender belong to a different message entirely.

Making matters worse, it’s not always true that the actual message belongs in the thread when the messages organized by thread contain an apparent interloper. Sometimes an apparent interloper is a real interloper. So I have to read it to check. I can’t rely on the message actually belonging in the thread, the way most of the apparent interlopers do.

Also, I don’t know how to manually change the wrongly displayed subject and sender so that they correspond to the subject and sender of the message that is actually displayed when the line in the top panel is clicked…

The “junk” issue comes up because, since I can’t rely on the message being what the one-liner says it is, I have to read all 22,000 messages I imported in order to assess which threads really are junk. If I could simply trash all the threads with an obvious junk subject line (and I know a lot of them! ), I could save almost half the work.