There is a simple command that can be used to make sure that the basic configuration of sendmail is correct:
echo \$Z | sendmail -d0.1
The output of that command should look like:
Version 8.13.1
Compiled with: DNSMAP HESIOD HES_GETMAILHOST LDAPMAP LOG MAP_REGEX
MATCHGECOS MILTER MIME7TO8 MIME8TO7 NAMED_BIND NETINET NETINET6
NETUNIX NEWDB NIS PIPELINING SASLv2 SCANF SOCKETMAP STARTTLS
TCPWRAPPERS USERDB USE_LDAP_INIT
============ SYSTEM IDENTITY (after readcf) ============
(short domain name) $w = host-name
(canonical domain name) $j = host-name.domain.com
(subdomain name) $m = domain.com
(node name) $k = host-name
========================================================
