Agenda: postfix-exercise2.txt

REMOTE MAIL CONFIGURATION
-------------------------

1. Let's configure our postfix to accept mail for our newly created domain!

    * First, find out what domains postfix is already configured
      to accept:

    # postconf -n mydestination

      You should see:

    mydestination = $myhostname, localhost.$mydomain, localhost

    * Let's add our domain -- the one we created in the DNS delegation exercises
      For example, if your domain is "MYNAME.ws.nsrc.org":

    # cd /etc/postfix/
    # postconf -e mydestination='$myhostname, localhost.$mydomain, localhost, MYNAME.ws.nsrc.org'

    (of course, use your own domain here, NOT MYNAME!)

    * View the contents of main.cf, and make sure that the new configuration
      for "mydestination" is there:

    # grep mydestination main.cf
    ...
    mydestination = $myhostname, localhost.$mydomain, localhost, MYNAME.ws.nsrc.org

    * Tell postfix to reload the configuration

    # postfix reload

2. Send an email to the user "sysadm" at your domain:

        # su - sysadm
    $ echo "test to my new domain" | mutt -s "test to MYNAME" sysadm@MYNAME.ws.nsrc.org

    $ tail /var/log/maillog

    $ mutt

    * Check that the mail has arrived in your mailbox!  Remember the 'h'
        command.

3. Reconfigure your DNS so that you have an MX for your domain.

    * If your domain is called "MYNAME" (MNAME.ws.nsrc.org),
      and your PC is "pcX", then, add the following to your
      /etc/bind/db.MYNAME.ws.nsrc.org

      (for example, after the NS records)

        ...
        NS      pcX.ws.nsrc.org.
        NS      pcY.ws.nsrc.org.

        MX  10  pcX.ws.nsrc.org.
        ...

    * MAKE SURE that you are pointing to YOUR ws and not someone else's!

    * REMEMBER THE SERIAL NUMBER!

    * Reload your zone (rndc reload ...)

4. Use dig to verify that you have configured the DNS correctly:

    # dig @pcX MX MYNAME.ws.nsrc.org

    (where X is your own PC, but also the slaves of your zone!)

    * Is your MX published ?
    * Do your slaves have the MX as well ?

5. You still need to tell Postfix to use your new domain name as its
   Origin -- meaning, what the mails coming out will have after @:

   * edit /etc/postfix/main.cf, find the line:

myorigin = /etc/mailname

        So the name if stored in the file /etc/mailname.

        Change the contents of /etc/mailname, and put in:

MYNAME.ws.nsrc.org

   * Now reload postfix

   # postfix reload

6. Send mail to others

        # echo "hello from here" | mail -s "hello from MYNAME" sysadm@OTHERNAME.ws.nsrc.org
        (OTHERNAME = someone else's domain in the room)

        * Check that they receive your mail AND that the email they see from you is:

        sysadm@MYNAME.ws.nsrc.org
        
7. Now, ask others to send mail to "sysadm@MYNAME.ws.nsrc.org"

    # echo "hello from there" | mail -s "hello from OTHERNAME" sysadm@MYNAME.ws.nsrc.org

8. Check that you are receiving the mail in your sysadm account:

    $ mutt

   We probably don't have a connection to the Internet, but if we did, we could
   send mail FROM "gmail.com" or somewhere else, and send mail TO our new
   domain.