RHCE Study Notes - SMTP

Study notes for any exam are difficult enough to find, but RHCE material seems even more scarce. This article tells how to prepare for one of the objectives, which is configuration of an SMTP server.

RHCE Study Notes
I wrote up some study notes as I was preparing for the RCHE exam. Here are some quick notes based on the official RedHat objectives, labs, and possible questions I thought might be reasonable requests.

SMTP Related Questions
install sendmail, sendmail-cf, sendmail-doc (optional)

Q: Configure mail server to accept internet email
A: modify /etc/mail/sendmail.mc
1) cd /etc/mail
2) vi /etc/mail/sendmail.mc
search for 127.0, put dnl at the front of the line
3) make
or m4 sendmail.mc > sendmail.cf
service sendmail restart
Q: Mail alias
A: modify /etc/aliases, run newaliases
Q: Receive mail for DomainX.example.com
A: modify sendmail mc as above, and add domain to /etc/mail/local-host-names
domainx.example.com
Debugging:
mail -v root
mailq, mailq -Ac
sendmail -q
tail -f /var/log/maillog

Configure Sendmail as a Server for Other Clients

A little more detail...

as root, or sudo

1. backup your /etc/mail/sendmail.mc and sendmail.cf files
   
2. vi /etc/mail/sendmail.mc

Search for a line with 127, and comment the line by placing "dnl #" at the beginning
Change this line
DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA')
to this
dnl # DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA')dnl

3. m4 /etc/mail/sendmail.mc > /etc/mail/sendmail.cf


4. /sbin/service sendmail restart


5. /sbin/chkconfig sendmail on

Debugging:
mail -v root
mailq, mailq -Ac
sendmail -q
tail -f /var/log/maillog

Links
For more details, see the Red Hat Reference Guide
https://www.redhat.com/docs/manuals/enterprise/RHEL-4-Manual/ref-guide/s1-email-mta.html

And LinuxSelfHelp
http://www.linuxselfhelp.com/quick/sendmail.html

rhce linux