As reported by someone I sent a response via Fedora squirrelmail 'It seems as though SquirrelMail's support for the "In-Reply-To" and "References" email headers is broken so that mailing list threads get broken when you reply using SquirrelMail. I've informed Jon Angliss at SM and they sent me a reply with the ff. bug number. Apparently, the fix will come out in ver. 1.4.12 and I suggest you upgrade as soon as it's released: http://squirrelmail.org/bugs/1810659' Please update as soon as upstream releases 1.4.12
Changing version to '9' as part of upcoming Fedora 9 GA. More information and reason for this action is here: http://fedoraproject.org/wiki/BugZappers/HouseKeeping
fc9 version currently 1.4.13.