Follow these steps to:
- ensure dns client configuration is in place and enabled;
- verify mail exchanger lookups are successful (if using DNS for mail exchanger lookups).
- To resolve error conditions, consult your DNS or Sendmail administrator for proper configuration parameters for your environment.
Is system configured as a DNS client:
Solaris 8, 9 and 10:
/etc/nsswitch.conf “hosts:” line contains “dns” keyword
/etc/resolv.conf exists with a minimum configuration of at least 2 (3 preferred) nameserver IP addresses