Hello. i am new to zimbra collabrative suite. i have installed ZCS 7 on Red Hat Enterprise Linux 5. during installation it gave me the messages:

No results returned for A lookup of mail.zimbra.com (mail.zimbra.com is my domain name).
Checked nameservers:

DNS error resolving mail.zimbra.com
It is suggested that the hostname be resolveable via DNS
change hostname. i selected no.


DNS error- none of the MX records for mail.zimbra.com resolve to this host
change domain name
i selected no.

after completing the installation i created two accounts. i sent mail from one to other. i got the message sent but it is not delivered in the other inbox. kindly help me out.