We've finally resolved a problem we were having with our Kana software and our Exchange 2003 migration. The issue began when we replaced our Exchange 5.5 SMTP servers with Exchange 2003. Messages that would normally come in fine from our Kana web form began comming in garbled. At first we thought it could be the message format. Playing with the message format settings revealed that if we set the content type to plain text and the character type to ASCII then the message body would come in fine except for the xml code. At this point we were getting the xml code that was normally in the message body as an attachment.
What we were able to resolve is that by still having Exchange 5.5 servers as bridgehead servers, our messages where being spun through different protocols (SMTP to RPC to SMTP again). When we tried to use only SMTP communication the messages came in fine. We tested and verified this by putting the mailboxes that were receiving KANA emails directly on the SMTP servers (no more RPC communication).