@nagendra Zimbra needs just a few things to change the IP address:
- hostname must match the IP address (check that /etc/hosts is correct, and reports the right name of the zimbra machine)
- you must have the right IP address in zimbraMtaMyNetworks:
as zimbra user,
zmprov ms <yourmailserverfullname> zimbraMtaMyNetworks '127.0.0.1/8 192.168.4.0/16 <otherIPrangesyouneed>' - execute as zimbra user
postfix reload
and
postconf mynetworks
to check that everything is correct.
If you use an external dns server, make sure it returns the correct results for your changed IP.