Sendmail 8.13.3 Securing Mailing Solution

1. To establish a Telnet session with the localhost, enter the following command:
% telnet localhost 25
The following output displays:
Trying...
Connected to localhost.<domain-name>
Escape character is '^]'.
220 <hostname> <domain-name>ESMTP Sendmail @(#)Sendmail
version 8.13.3 - Revision 1.000
- 1st August,2006/8.13.3; Thu, 5 Jul 2007 18:37:50 +0530
(IST)
2. To send an EHLO message to the Sendmail 8.13.3 server, enter the following at the
Telnet prompt:
EHLO localhost
The following output displays:
250-<hostname> <domain-name> Hello localhost [127.0.0.1], pleased to meet you its
250-ENHANCEDSTATUSCODES
250-DSN
250-AUTH CRAM-MD5 LOGIN PLAIN
250-AUTH CRAM-MD5 LOGIN PLAIN
250 HELP
NOTE: Ensure that you get a response similar to the previous output from the
Sendmail 8.13.3 server
3. To quit the Telnet session, enter the following command:
Quit
The following output displays:
221 2.0.0 <hostname> <domain-name> closing connection
Connection closed by foreign host.
NOTE: If you encounter any problem while verifying the SASL setup, check the syslog
file using the mtail command for any security problems (for example, unsafe files).
If you are unable to identify the problem, increase the log level to 13 in the
/etc/mail/sendmail.cf, and restart the Sendmail 8.13.3 server using the following
commands:
/sbin/init.d/sendmail stop
/sbin/init.d/sendmail start
Using Sendmail 8.13.3 with AUTH
This section discusses how to use Sendmail 8.13.3 with the AUTH feature.
Follow this procedure if you use Sendmail 8.13.3 only to transfer mail from your local
computer to a mail server that requires SMTP AUTH authentication:
Using Sendmail 8.13.3 with AUTH 25