I have /flatfwd in the gwia config file.
I have it checked in C1.
I have restarted GWIA multiple times.
I have NOTHING in the FROM field in the rule.
I have NOTHING in the body text of the rule. NOTHING anywhere except in the TO field.
This happens with external and internal emails.

When a message gets forwarded, it is still tagged as FROM: my email account.
I've tried a number of variations in the format of the forwarding address:

rh-do2.GWIA:<hotmail address>
RH-DO2.GWIA:<hotmail address> - checking case sensitivity (listed as lower case in C1)
GWIA:<hotmail address>
<hotmail address>

All 4 work exactly the same.
When I hit 'reply' from hotmail, it goes to my groupwise email, not the email of the sender, as it should according to my understanding of flat forwarding.