SMTP Forwarding rules

Copper Contributor

We have a requirement to forward physician emails to their private email accounts and utilize SMTP forwarding, which works fine. Now we need to modify the forwarding to only allow internal originating emails to be forwarded to their private accounts and none of the ones received from an external source. Example would be is our domain if the email is from then it is allowed to be forwarded, via SMTP forwarding to the private account.  If the email is from then is is NOT allowed to be forwarded.  We have tried several things 

1 Reply
Use an Inbox or Mail flow rule for that, the built-in forwarding controls don't allow any granularity.