I have just setup a new 8.0.4 server and I am getting messages sent from zimbra@countrycode.mydomain.com which are addressed to zimbra@countrycode.mydomain.com.

The Ubuntu hostname is zimbra.us.mydomain.com
The domain that I have configured within zimbra is mydomain.com.
The admin accounts is admin@mydomain.com

I found that there are lots of Ubuntu system messages being generated by cron daemon from root@us.mydomain.com to zimbra@us.mydomain.com.

Where is this set? I cannot find where the server has zimbra@us.mydomain.com set so that I can change it to admin@mydomain.com