FOCUS[[Category:OPS335]][[Category: OPS335 Labs]]==Basic Mail (Postfix) Setup==This lab will show you how to set up a Postfix email server using a Fedora 13 installed PC20 installation.*You will need at least two systems to do this lab. The first could be Fedora on If for some reason you have not set up your removable hard drive while the second could be a virtual machinemachines, do so before continuing.PART A - PrerequisitesYour hard drive should {{Admon/important|Prerequistites|Ensure all machines have Fedora 13, 64 bit Live edition already installedbeen updated and that the clocks are set to the correct date and time.}}You should have at least one VM installed: also Fedora 13, 64 bit Live edition.=== Testing your network ===Both *Start Firefox on your host and guest should have default firewalls enabledauthenticate yourself on Senenet with your Seneca account.Both *Ensure you can surf the web on your host and guest should have SELinux enabledmachine.Both As your host and guest should have all software updatedbe using VM 1 as its DNS server, you will need to start it as well. [ yum update ]*Ensure you can access the clocks web on both machines are set your VM2 (you can use wget or lynx for that). NOTE: you should not have to authenticate yourself on the correct date and timeguest.PART B - Testing your network

Start Firefox on your host and authenticate yourself on Sene2net with your LEARN account.Ensure you can surf === Reviewing the web on your host machine.Start Firefox on your guest.Ensure you can surf the web on your guest. NOTE: you should not have to authenticate yourself on the guest.PART C - Testing email to the outside world using mailx and sendmailmail command ===

Sendmail is installed  ===Install and configure Postfix on a VM===*On Vm 2 do the following:**Check the status of the sendmail service. If it show up as running by default on Fedora 13 so there or enabled, stop and disable it. **Install Postfix and mail yum install postfix mailx**While that is no need installing, you may wish to read the mail manual page to install remind yourself how itworks.Install mailx on both **Edit the host Postfix configuration file, /etc/postfix/main.cf, and change the guestfollowing parameters: mydomain = <senecaID>.org myorigin = $mydomain mynetworks = 127.0.0.0/8, 192.168. [ yum install mailx ]X.0/24 relay_domains = inet_interfaces=all {{Admon/important|Warning|Make sure there are no other uncommented copies of these parameters in the file.}} **Create the database file of mail aliases postalias hash:/etc/aliases **Start and enable Postfix: systemctl start postfix.service systemctl enable postfix.service **Check your /var/log/messages file to see that your postfix servers started without error.***If there are any errors, correct them before continuing. ===Testing mail with the internet===*Test email from the host your machine by sending an email to your LEARN Seneca account. [ mail -s "PART C3" xxxxxx@learn.senecac.on.ca ]<Your Seneca email address>Note: xxxxxx <Your Seneca email address> is your LEARN IDSeneca email address.<br />

*Check your LEARN learn email to see if you got the email(note that it may take a few minutes to arrive, so you may also wish to try an alternate email account if you have one). If When you did do receive that email make a note of the return address.*If you did not receive the mail, check the mail logs on your machine to determine what the error is.*Test email from the host by sending an email to your LEARN Seneca account. [ mail -s "PART C4" -r hacker@evil.com xxxxxx@learn.senecac.on.ca ]Note: xxxxxx is your LEARN ID.<Your Seneca email address><br />

*Check your LEARN Seneca email to see if you got the email. If you did make a note of the return address.*Repeat the steps 3 and 4 on the guest machine.PART D - for 'Install and configure Configure PostfixOn both machines do the following:Stop sendmail. [ service sendmail stop ]Install Postfix - yum install postfixEdit the Postfix configuration file, /etc/postfix/main.cf, and change the following lines:mydomain = exampleon a vm' on your VM 3.orgmyorigin = $mydomaininet_interfaces = allmynetworks = 127.0.0.0/8, 192.168.122.0/24relay_domains =Start Postfix [ service postfix start ] on both host and guest machinesPART E - Testing email using IP Addresses

If you have problems with the following you may have to set SELinux to permissive mode and/or adjust ===Testing email using IP Addresses===*Adjust your firewall to allow traffic to/from port 25on both VMs.**Also check your /var/log/maillog file to see the log entries that get created when mail is sent and received, and when something goes wrong.*Try sending an email from your guest vm2 to your hostvm3. [ mail -s "PART E2" yyyyyy@[192.168.122X.1] 4]Note: yyyyyy is your host Seneca ID<br />

*Try sending an email from your host vm3 to your guestvm2. [ mail -s "PART E3" zzzzzzroot@[192.168.122X.ZZZ] 3]Note: zzzzzz is your guest IDNote: ZZZ is your guest IP addressPART F - Set up a DNS server

Refer to Lab #3 and set up a DNS server on your ===Test email using host.names===Set your *Use the host name and hostname commands to f13.Set check that each of your guest name to vm01machines has the same hostname that the DNS service says they have.Set your domain name to example.org.Test your DNS **Restart postfix if you change the hostname on both host and guest to ensure it works properly.PART F - Test email using host namesNow try sending either mail to yourself on both machinesserver. For example, as joker on f13, use the command:

Now try sending mail to yourself on both machines. For example, as <senecaID> on VM 3, use the command: $ mail joker<senecaID>@f13vm2.<yourdomain>.org

*Now enter the body of your letter. When you're done, enter a period (.) in column 1 on the last line of your letter. This will signal end-of-file and your letter will be mailed. You should end up back at the $ prompt. If you mess up use CTRL-C to cancel the email, DO NOT USE CTRL-Z. *Use the mailq command on both machines (you will need to be root) to view the mail queue.

PART G - Test your configuration and view your logsRestart your ==Completing the Lab==Upon completion of this lab you should have postfix mail servers running on both two machines, and starting automatically when they do.Check your /var/log/messages file to see that your postfix These servers started without error.Send some emails from must have sent email both guest and host to ways between each other (from VM 2 to VM 3, and from VM 3 to the outside world.Check your /var/log/maillog file VM 2), and to see that your seneca email messages were sent correctly(or other external mail server).PART H - Learning the mail commandRead the mail manual page and learn how it works.PART I - Answer the following Exploration questions and and email them to your teacher in ASCII text format.:What is your full name and 9-digit Seneca student ID?Include a copy of your main.cf file on vm01 (your guest) with this lab - but delete all commented and blank lines first - like this. [ cat /etc/postfix/main.cf | grep -v ^# | awk 'NF > 0 {print $0}'What is the output of did changing the iptables-save command on both your host and guest machinesrelay_domains parameter do?#What firewall rule or rules, if any, did you have to enter on the guest and/or host so that email to/from each other between your VMs would work?#What is the meaning of the square brackets surrounding the IP address in PART Ethe examples?#What were your the results to PART Gof sending email between the VMs? Show log segments to verify your answers.