Well, I Google'd for a while... And on the page http://extelligence.ringlet.net/roam/archives/000018.html I found;
Found in microsoft.public.outlook:
<http://groups.google.com/groups?threadm=%23GDzS5VDEHA.3404%40TK2MSFTNGP10. phx.gbl>
<http://groups.google.com/groups?threadm=18af01c3f66b%2413fb0f60%243501280a %40phx.gbl>
<http://groups.google.com/groups?threadm=5cbb01c3e5bc%24f9876c00%24a001280a %40phx.gbl>
<http://groups.google.com/groups?threadm=OZhbLZO0DHA.3496%40TK2MSFTNGP11.ph x.gbl>
Other sightings:
<http://www.slipstick.com/emo/2003/up031211.htm>
Since the Message-ID is supposed to be added by the server if the MUA omits it, what servers are these clients using that fail to add the ID?
