My organization deals closely with other external organizations that
have the need to send mass email to all of our users on occasion. They
way this is handled now is via the use of multiple external entities
and a complex series of rules that foward from one external entitity
to another that then fowards to a system distribution list. The rules
ensure that only predefined senders messages are fowarded. Also,
reply's and out of office email is not forward to the group either.
If the users want to reply, the need to send a new email directly to
the original sender.

This is what existed when I inherited the system and has not changed.
It works OK, except when the external organizations change the sender
email that they use and do not tell us, then nothing works.

How do others handle this scenario? Are there some new features in
2012 that did not exist when this was setup back in the GW 6.5 days?

The users sending the messages do not have access to our
system/network. Allowing them to login with an external ID or resouce
ID is not an option.

Any advice would be appreciatetd.