This line:
Code:
192.168.0.90 mail.domain.com fedora
is still wrong.
According to that information, your mail server should have a name of 'mail' not 'fedora' and the line should read:
Code:
192.168.0.90 mail.domain.com mail
Is this a new install? I'm guessing that you installed it and gave the domain localhost.localdomain to zimbra when it was installed, is that right?