Please don’t create unconditional filters (or using conditions that will absolutely be met by all inbound mail) that forward emails. If an email bounces the bounce forwards, which bounces, which forwards, which bounces, which forwards, and then breaks the entire outbound infrastructure by filling it with tens of thousands of emails in a matter of hours until I have to shut off your entire service after briefly disabling all outbound email for customers to stop it. You can create email forwarders via our control panel. Sieve filters are too literal for this job and automating protection against it would break needed functionality.
As for the error, it’s quite literal. Google doesn’t accept emails without a From header, which appears to be what you’re sending them in this case. If you’re certain that the From headers are in place in the email that is being redirected, use the Feedback tool in Crossbox to notify the developers, but ideally you won’t be able to test a fix because you’ll want to set up actual email forwarding in our panel.