Please refer to the linked post how to create a rule and define conditions, in this post I will only modify actions.
Modify Forward ActionEdit already created rule. Select rule and click Actions button and select Edit menu. Add second envelope recipient to the message, click Add button and Add Envelope Recipient menu. Put email@example.com email address in the address field. Click OK button.
From the list select Add Message Header entry and click Edit button. In the Header Value field put ;firstname.lastname@example.org email address. Don’t forget about semicolon, it’s needed because we add another email address to the MIME header. Click OK button.
Click OK button to close the rule wizard and click Save All button to preserve changes.
Now when a message will match conditions it will be forwarded to two recipients. They both will receive a message as carbon copy recipients.
Check what else could be done with MSH Traffic Policy for Zimbra, Postfix and Sendmail…