domain MX record not found while installing Zimbra

Question

I am getting this error:

DNS ERROR resolving MX for localhost.localdomain It is suggested that
the domain name have an MX record configured in DNS Re-Enter domain
name? [Yes]

named file:

$ttl 38400
localhost.localdomain.  IN  SOA centoslpt.localhost.localdomain.
test.localhost.localdomain. (           1357549995          10800           3600            604800              38400 )
localhost.localdomain.  IN  NS         
centoslpt.localhost.localdomain.
centoslpt.localhost.localdomain.    IN  A   192.168.1.15
mail.localhost.localdomain. IN  MX  10 192.168.1.15

why is MX record not detected pls, I am using BIND and webmin.

Answer 1

MX records should be names, not addresses. The address will be looked up from the name using A or AAAA records.

So you should have something more like:

mail.localhost.localdomain. IN  A  192.168.1.15
mail.localhost.localdomain. IN  MX  10 mail.localhost.localdomain.

Note that only A and AAAA records are used: the FQDN referred to by an MX entry should have valid A and/or AAAA records, CNAME records will not be used.

Also, the message suggests it is looking for an MX entry for localhost.localdomain not mail.localhost.localdomain - so you may need:

localhost.localdomain. IN  MX  10 mail.localhost.localdomain.

instead or as well. If you are wanting to serve mail for <users>@mail.localhost.localdomain and not <users>@localhost.localdomain then you may have your hostname set wrong elsewhere (the Zimbra admin/install forums or serverfault.com may be a better place to ask about that (in fact this question would better sit on serverfault.com than superuser.com IMO)).