RE: embed issue id into email subject

[Joao Prado Maia]

Christian, 

> You could try the 'References:' header, which is rarely used, and even
> then primarily by Usenet postings, but I believe it passes through so
> it's worth a try.  I don't have time to try this out myself, but if
> anyone has a go...
> 

Not good enough. Outlook doesn't send any of those headers
(References/In-Reply-To, or even Message-ID). See this blog posting for
more details:

  http://pessoal.org/blog/?p=30

--Joao