https://www.vavai.net/2008/10/zimbra-tips-archiving-how-to-make-an-archive-for-every-incoming-and-outgoing-mail/
El archivo actualmente está en: /opt/zimbra/common/conf/main.cf
Add the line always_bcc = accountname@domainname.com (adjust the setting with your preference)
always_bcc = archive@archive.com
Restart Zimbra
su zimbra
zmcontrol stop
zmcontrol start