We do not support forwarding emails to domains hosted outside the same hosting account. This means you cannot set up forwarders to forward to e.g. gmail.com or hotmail.com addresses or similar.
The main reasoning boils down to increased chances of IPs and domains being marked as spam. DMARC, DKIM and SPF violations. We do not implement SRS for the same reason of increased chances of IPs being marked as spam.
