sendmail: check version, compile flags, system identity
These options to sendmail will give you some useful version and configuration information.
sendmail -d0.1 -bt < /dev/null
output looks somthing like so:
Version 8.12.9p2
Compiled with: DNSMAP LOG MAP_REGEX MATCHGECOS MILTER MIME7TO8 MIME8TO7
NAMED_BIND NETINET NETINET6 NETUNIX NEWDB NIS PIPELINING SCANF
STARTTLS TCPWRAPPERS USERDB XDEBUG
============ SYSTEM IDENTITY (after readcf) ============
(short domain name) $w = host
(canonical domain name) $j = host.domain.com
(subdomain name) $m = domain.com
(node name) $k = host.domain.com
========================================================
ADDRESS TEST MODE (ruleset 3 NOT automatically invoked)
Enter





