If you would like to define selective alwyas bcc for sender or recipients read this post.
You need to select which messages should get additional BCC addresses. Go to Conditions tab, click button Add and select Message Sender menu. For our scenario we assume that we want to add BCC recipients to all messages which are from our domain, ie. domain.net.
|Email addresses can be matched as exact, with wildcards or regular expressions.|
Add Envelope Recipient action
This action will work like "add bcc recipient", it will add only envelope recipient without BCC header. Recipient of this message will not see whom also received this message.
|Add Envelope Recipient is only one of many actions which could be used on messages.|
In new opened window provide an address for the mailbox to which you want to forward messages. Now once again choose Add Envelope Recipient action. Add as many addresses as you want.
|You can add as many BCC recipients as you want.|
If you would like to do more with your mail server, check other milters for Zimbra, Postfix and Sendmail.