Hi, Alex. I know you got a response to this from our support staff, but I wanted to post the reason just in case anyone else sees this issue.
Forwarding from a local domain to a local domain shouldn't be an issue. However, if there are any filters in place, then that *could* impact the forward. In your case, there was a Internal Blocked Senders filter set that was removing the forward.
Thanks for the question.
Derek Curtis
COO
SmarterTools Inc.
www.smartertools.com