Sendmail: Disable outbound mail

[Frank DiPrete]

I have sendmail running under the default configuration to listen on
port 25 and only accept mail from localhost. However, I would like to
configure it to only be able to send mail to localhost. I basically
don't want mail going off the machine. This is only being used for
internal email. TIA. 


in /etc/mail/access is a list of domains, machines, and/or networks that
sendmail will accept, reject, or relay mail for.

so, to accept mail from machines and on your net and localhost rather
than relay, use OK instead of RELAY

i.e

# Check the /usr/share/doc/sendmail/README.cf file for a description
# of the format of this file. (search for access_db in that file)
# The /usr/share/doc/sendmail/README.cf is part of the sendmail-doc
# package.
#
# by default we allow relaying from localhost...
localhost.localdomain           OK
localhost                       OK
127.0.0.1                       OK
yourdomain.com			OK


the last entry assumes you have dns set up for your lan (with an
appropriate MX record)


after editing the fail do a "make restart" from /etc/mail