A colleague reminded me of an old issue. It’s actually quite a rare Outlook setting, I would say, and it’s not one that I use. Some people use it and love it. The setting is :
“In folders other than the inbox, save replies with original message”
I wrote about an issue quite some time ago where this didn’t work with the Enterprise Vault 9.x series of Outlook Add-ins:
I’ve just been looking at this in the upcoming 10.0.1 Client, and the good news is that it is fixed again.