After upgrade to Zimbra 6.0.5 we've got a problem with forwarding messages matching the filter's conditions of mailbox.
I have address email@example.com with alias firstname.lastname@example.org.
The filter is configured to forward messages with To = email@example.com to another address firstname.lastname@example.org.
Everything works perfectly except email@example.com gets mail with header "From:" set to firstname.lastname@example.org. And address of original sender gets lost forever.