I have some problems about domain name zimbra on CenTOS.Like you.my old domain on exchange is username@localdomain.com,after migrating their domain name became username@localhost.localdomain.com.But ,I just want username@localdomain.com.Why it added localhost.localdomain.com.I looked at /etc/hosts files.In these files,I see that
my ip address localhost.localdomain.com localhost does the zimbra take this instead of domain name?

Thnak you