For now it works weird, wiki documentation also does not match current version.
CWP also does not change hostname in CentOS itself (at least for me it is such), I mean
https://support.rackspace.com/how-to/centos-hostname-change/.
Hence for outgoing email in headers you have old hostname used by amavisd-new in X-Virus-Scanned: amavisd-new and below.