Sendmail 8.13.3 Securing Mailing Solution

1. Uncomment the following entries in the /etc/mail/sendmail.cf file:

C{TrustAuthMech}GSSAPI DIGEST-MD5 LOGIN PLAIN

O AuthMechanisms=GSSAPI KERBEROS_V4 DIGEST-MD5 CRAM-MD5

O DefaultAuthInfo=/etc/mail/default-auth-info

O AuthOptions=A

NOTE: If these entries are already uncommented, ensure that you assign the

previously mentioned values to the TrustAuthMech, AuthMechanisms,

DefaultAuthInfo, and AuthOptions options.

2. Create the /usr/lib/sasl2/Sendmail.conf file with following entries:

pwcheck_method: auxprop mech_list:

Ensure that you have provided permission only for the superuser to access the

/usr/lib/sasl2/Sendmail.conf file, as follows:

# cd /usr/lib/sasl2/

# chmod 600 Sendmail.conf

3. To set the SASL password of the user for server programs and SASL mechanisms

that use the standard libsasl database of user secrets, enter the following

command:

saslpasswd2 -a appname -c [–u] <server_domain_name> userid

The saslpasswd2 command prompts and accepts the SASL password, and creates

the /etc/sasldb2 file.

Example 1 Sample saslpasswd2 Command

Following is a sample saslpasswd2 command:

saslpasswd2 -a Sendmail -c –u <domain-name> root

where:

Sendmail Specifies the application name.

<domain-name> Specifies the domain name of the Sendmail 8.13.3 server.

root Specifies the user ID.

4. To restart the Sendmail 8.13.3 server, enter the following commands:

/sbin/init.d/sendmail stop

/sbin/init.d/sendmail start

Verifying the SASL Configuration

Follow this procedure to ensure that SASL is set up properly on the Sendmail 8.13.3

server: