Introduction to sendmail in Linux

Sendmail is an email system. during installation, the default configuration file sendmailcf will be installed under etc. This configuration file can work only for SMTP sites, but not for UUCP

Sendmail is an email system. when installed, the default configuration file sendmail. cf will be installed under/etc. This configuration file can work only on SMTP sites, but not on UUCP sites. if you want to use UUCP for mail transmission, you have to generate a new sendmail. cf. in this case, you need to install the m4 and sendmail source code packages. please read README in The sendmail source code to obtain more detailed methods for creating the snedmail configuration file. You can also see a good reference book on sendmail published by O'Reilly & Associates (by Bryan Costales ).

A common sendmail configuration uses one machine as the mail gateway for all hosts in the network. For example, in Red Hat software, we have a machine named mail.redhat.com to process all our emails. We only need to simply add the name of the machine mail.redhat.com whose email is to be processed to/etc/sendmail. cw. The following is an example of this file:

# Sendmail. cw-include all aliases for your machine # here.torgo.redhat.compoodle.redhat.comdevel.redhat.com

Edit/etc/sendmail. cf in torgo, poodle, and devel machines to send emails like mail.redhat.com and forward local emails to redhat.com. Edit the rows containing DH and DM:

# Who I send unqualified names to # (null means deliver locally) DRmail.redhat.com # who gets all local email trafficDHmail.redhat.com # who I masquerade as (null for no masquerading) DMredhat.com

In this configuration, all sent emails are sent by the cluster redhat.com, and any emails sent to torgo.redhat.com and other machines are sent to mail.redhat.com.

Please note that if you configure your system to send an email as another machine, any emails for the purpose of this system will be sent to that host, for example, all the Mail root@poodle.redhat.com log files that are regularly generated by the cron process are sent to the root@mail.redhat.com.