Did you ever get an answer? I've posted a similar question to MSDN forums and am awaiting a response:
Here's my situation and question relating to MOSS 3.0 (Not Sharepoint Server 2007).
A discussion board has "Incoming E-Mail Settings" to allow the list to receive email.
When a discussion is started on the Discussion Board via an email to the list's email address a new threaded discussion is started.
If one reply's to that message, the reply is added to that thread as one would expect.
However, if I don't reply to that email, but create a new email, even if I use the same subject line, a new thread is created, so I know of course Sharepoint is using some other characteristics of the message to recognise messages as replies to a discussion thread. What I can't figure out is that even if I go into Outlook -> Sent Items - Open the items, and go into actions -> other actions - View Source , BOTH files are identical.
Additionally, when I "Connect to Outlook", and access the list, and 'Post' to an existing discussion, it invariably adds a new discussion thread to the list.
Question(s):
1) What field(s) does SPS list use to identify an email as part of an existing thread?
2) Is it possible to create a new email and somehow tag it so that it attaches to a specific thread (and does not create a new thread)?
Bonus points for this one:
Is there a way to configure SPS via a list workflow to attach an email to a thread if it contains a specifc string in an email subject? Basically, we have a ticket tracking system which assigns unique 9 digit numbers. It would be awesome if I could have any email with the number '123456789' attach to an existing thread with subject number 123456789 or create a new one.