I thought I had this integrated right, but when I try to send an e-mail to the list (email@example.com), Zimbra acts as if it's a bad address. I can send e-mails to existing accounts (firstname.lastname@example.org) fine.
The problem I think is in the postfix config .. the directions say to change these lines:
virtual_alias_maps = ldap:/opt/zimbra/conf/ldap-vam.cf,hash:/usr/local/mailman/data/virtual-mailman
alias_maps = hash:/etc/aliases,hash:/usr/local/mailman/data/aliases
I changed the first one with zmlocalconfig, the second I couldn't find in there, so I changed it in main.cf.default, but when restarting zimbra it doesn't seem to make it's way into main.cf. That's one issue and could end up resolving the whole thing.
Another odd problem is when I have that virtual_alias_maps line modified and try to send any email, local or not, Zimbra hangs and eventually returns a error.