IMAP: How to implement GMail-like threaded conversations view

[Martin]

Currently I am trying to get used to Python's imaplib and email
modules.
I'like to create a webmail client simmilar to GMail.

My Questions:
a) Is there any feature hidden in Python's built-in modules (imaplib,
email) that already can group all my mails into threads?

b) If not a... what would be the best way to implement this?

I can think of two approaches:
b.1) Use the "References:" field of the messages in order to find out
which messages are related to each other.

I tried a first implementation which works quite well but I don't know
if there can occur situations where one message is related to two
parents. Also I don't know what happens if someone is too lazy to type
my address. He might click at "Reply", delete topic and old mail-text
and compose a new mail. Theoretically his mail client would set the
"References:" field accordingly never the less, wouldn't it? Therefore
my mail client would consider that completely new mail as part of an
older conversation.

The thoughts above might lead to the second approach:

b.2) Use the "Subject:" field of the messages.

I also tried this implementation and it also works (at first glance).
I stripped all subjects of all mails so that all those "Re:", "Fw:"
tags at the beginning get deleted. Afterwards I grouped those having
the same subject and the same participants. Problem: I have no clue
what "Re:"-tags might exist around the world. I guess each mail client
and each language uses different ones, right?

c) Does anyone know good resources to gain more knowledge about imap /
mailing?
Currently I am using those sites as a reference:

http://www.devshed.com/c/a/Python/Python-Email-Libraries-part-2-IMAP/
(as a start *g)
http://tools.ietf.org/html/rfc3501
http://tools.ietf.org/html/rfc2822
http://docs.python.org/library/imaplib.html
http://docs.python.org/library/email.html

Maybe there are other sources of interest on the web? :)

This is my first post in this newsgroup. So:

"Hello everybody!" :-)

I've been reading this group for quite a while and I am really
astonished how fast people give valuable answers here. This is a
really great community! Many thanks in advance for all ideas!

Greetz,
Martin