# sendmail -d0.4 -bv root | grep Version
Version 8.14.7
^C
# sendmail -d0.1 -bt < /dev/null
Version 8.14.7
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
^C
#Or you can use the Telnet command to connect to the
Simple Mail Transfer Protocol (SMTP) port, i.e.,
well-known port 25, that Sendmail lisens for connections on. The
Sendmail banner will reveal the version number. You can terminate the
connection by typing quit.
$ telnet 127.0.0.1 25 Trying 127.0.0.1... Connected to 127.0.0.1. Escape character is '^]'. 220 example.com ESMTP Sendmail 8.14.7/8.14.7; Fri, 2 Dec 2016 21:10:07 -0500 quit 221 2.0.0 moonpoint.com closing connection Connection closed by foreign host. $
On a Linux distribution that uses the
RPM Package
Manager (RPM), such as CentOS, you can also issue the RPM command
rpm -qi sendmail.
$ rpm -qi sendmail | grep Version
Version : 8.14.7
$On a Debian distribution, such as Ubuntu, you can use apt-cache show sendmail.
$ apt-cache show sendmail | grep Version Version: 8.14.4-2ubuntu2.1 Version: 8.14.4-2ubuntu2 $