That shows me your Domino Administrators know what they are doing! ;)
Or it may have been stopped at RIM.
A couple of items:
1) Forwarding emails in that fashion, in some companies, may be a violation to IT policy and can be cause for termination!!
2) The error you are getting is because of anti-relaying. So for example, this would prevent someone from sending an email as
from their Blackberry.