Conversation grouping (Gmail style) is a great feature in Outlook >= 2007.
The problem is when emails in a conversation have different reply prefixes (e.g. forward or Fwd:). In English it's Re:, but in Polish it's: Odp:. So if a reply is sent from a language other than English in this version of Outlook, the thread is broken, i.e. another thread is created based on the prefix.
Has anyone found a fix to this problem?
Here a partial solution is described: http://www.trilithium.com/johan/2005/06/re-outlook/
I would like to fix this from another side; let's call it Client side.