In the desktop client under tools -> options -> outlook you can set a default template for imported emails .

This setting seems to be user specific and sets a row in [trustee_attr] WHERE [attr_name] = '[Settings]MsgImp_UseParentFolderTemplate'. This is only set for a subset of our users . 

Is there a place to set the default for this value?

It seems to already be the default for non msg files but the setup was before my time.