This lab will show you how to set up a '''Postfix ''' email server using a Fedora 20 installation('''MTA''') on your '''VM2''' and '''VM3''' machines.*You will need at least two systems also be setting up on your '''VM2''' and '''VM3''' machines the '''mailx''' package ('''MUA''') to do allow users to send and receive text-based mail messages. You should also be able to send email messages to your Seneca College email account. The diagram below shows the layout of the what this labshould be able to accomplish:  [[Image:email-setup. If for some reason you have not set up your virtual machines, do so before continuing.png]]

#Edit the Postfix configuration file: '''/etc/postfix/main.cf''' and edit this file to contain only the contents displayed below:<br><br>'''mydomain = senecaID.org'''<br>'''myorigin = $mydomain'''<br>'''mynetworks = 127.0.0.0/8, 192.168.X.0/24'''<br>'''relay_domains ='''<br>'''inet_interfaces=all'''<br><br>'''NOTE:''' Your MTA has the ability to resolve "fake" public address to an actual user account name. For example, if you have a user account called "msaul", you can have the MTA resolve the fake name "murray.saul" to the account name "msaul".<br>In order to do this you need to create an alias which is contained in the MTA's alias file.<br><br>#Edit the '''/etc/postfix/aliases''' file and add your first name as an alias to be resolved to your VM2's account name:<br><br>'''your-first-name''' &nbsp; &nbsp; &nbsp; '''your-vm2-regular-username'''<br><br>#In order to update the MTA's database for the newly-create alias, issue the following command:<br>'''postalias hash:/etc/aliases'''<br><br>#Finally, to start and enable your MTA, issue the following commands:<br><br>'''systemctl start postfix.service'''<br>'''systemctl enable postfix.service'''<br><br>#Check the '''/var/log/messages''' file to see that your MTA server started without error If there are any errors, correct them before continuing.

*We will now test to see if your MTA for your VM2 machine is correctly running by sending email messages to other servers (both within and outside your virtual network).  '''Perform the following steps:''' #Test email from your machine by sending an email to your Seneca account. using the following command:<br><br>'''mail -s "PART C3" <Your Seneca email address>Note: '''<Your Seneca email addressbr> is your Seneca email address.<br />Note'''NOTE: ''' after you type in your letter, enter a period in the first column on the last line and hit the ENTER key.<br><br>*#Check your 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). When you 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 your Host Machine by sending an email to your Seneca account. using the following command:<br><br>'''mail -s "PART C4" -r hacker@evil.com <Your Seneca email address>'''<br><br />Note: after you type in your letter, enter a period in the first column on the last line and hit the ENTER key.*#Check your Seneca email to see if you got the email. If you did make a note of the return address.*#Repeat the steps for INSTALL &amp; '''SETUP THE MAIL TRANSFER AGENT (MTA)'''Install and Configure Postfix on a vm' on ''INSTALL &amp; SETUP THE MAIL USER AGENT (MUA)''' for your VM 3'''VM3'''.

*If you were able to send e-mail to your Seneca e-mail account from your VM2 and VM3, then we should test to see if we can send email messages within our virtual private network.First, let's send a message using a static IP ADDRESS for each VM: '''Perform the following Steps:''' #Adjust your firewall (iptables) to allow traffic to port 25 on both VMs.**Also check # Check your '''/var/log/maillog ''' file to see the log entries that get created when mail is sent and received, and or notes when something goes wrong.*#Try sending an email from '''vm2 ''' to your '''vm3. ''' by issuing the command:<br><br>'''mail -s "PART E2" yyyyyy@[192.168.X.4]Note: yyyyyy is your Seneca ID'''<br><br />Note: the square brackets around the host IP address*#Try sending an email from your '''vm3 ''' to '''vm2. ''' by issuing the command:<br><br>'''mail -s "PART E3" root@[192.168.X.3] ''' <br><br>

Now try Let's complete this lab by sending mail to yourself on both machines. For example, as <senecaID> on VM 3, use the commandemail messages using our recently-created domain name: $ mail <senecaID>@vm2.<yourdomain>.orgthe machine will prompt for a subject: enter "testing" without the quotes.

*Now enter '''Perform the body of your letter. When youfollowing Steps:'''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 '''host''' and '''hostname''' commands to confirm that each of your machines has the same ''hostname'' and that the DNS service verifies this to be true.#Restart your MTA (postfix) server if you changed the hostname on either mail server.#Try sending mail to yourself on both machines. For example, as the username <senecaID> on VM 3, use the command:<br><br>$ mail <senecaID>@vm2.<yourdomain>.org<br><br>'''NOTE:''' the machine will prompt for a subject: enter "testing" without the quotes.<br><br>#Enter the body of your e-mail message. When you have completed entering your email message, enter a period (.) in column 1 on the last line of your letter. This will send the signal: '''end-of-file''' and your letter will be mailed. You should end up back at the shell prompt. If you make a mistake, use '''CTRL-C''' to cancel the email (DO <u>NOT</u> USE CTRL-Z).#Use the '''mailq ''' command on both machines (you will need to be root) to view the mail queue. Why would this command be useful for an administrator?#Use the mail command to check to see if you have received any mail.

'''Record steps, commands, and your observations in INVESTIGATION 2 in your OPS335 lab log-book'''  ==Completing the LabCOMPLETING THE LAB==

Exploration questions:==EXPLORATION QUESTIONS==