# grep smtp /etc/services
smtp 25/tcp mail # Simple Mail Transfer
smtp 25/udp mail # Simple Mail Transfer
# ps -ef | grep post
root 1078 1 0 Jul20 ? 00:00:07 /usr/lib/postfix/master
postfix 1082 1078 0 Jul20 ? 00:00:02 qmgr -l -t fifo -u
postfix 29291 1078 0 02:38 ? 00:00:00 pickup -l -t fifo –u
Configuring the mail server
the following assumptions apply:
- You have a full-time Internet connection
- This machine is the outgoing mail server.
- This machine is the incoming mail server.
- Only users of this machine will be using it for e-mail services.
From the initial YAST screen, choose Network Services. From the list of Network Services, choose Mail Transfer Agent. It will take a minute or two for YAST to read all the necessary information about the installed mail server and to determine the installation options available.
The first three options on the Connection Type screen—Permanent, Dial-up, and No Connection—are mutually exclusive, so choose the appropriate one for the installation. A Permanent connection is where the mail server is always connected to the Internet; a Dial-up connection requires a step to connect to the Internet; and No Connection means no connection to the Internet, so only local mail can be sent and delivered.
The last option on the Connection Type screen, Enable Virus Scanning (AmaViS), is an add-on feature that allows both inbound and outbound mail to be checked for viruses. For this example, choose Permanent, leave the virus option disabled, and then press Next.
The next screen, Outgoing Mail, allows you to enter the outbound mail server, but since this article assumes the local machine is the outgoing mail server, you don’t need to enter anything here. The Masquerading option allows mail to always appear to come from a central machine, instead of from the local machine. This is useful in situations such as a company that would like all e-mail to appear as:
Without masquerading, e-mail would appear as:
Many users prefer standardized e-mail addresses, which allow you to use central virus checking and provide a way to have only one machine accessible via the Internet for mail.
The Domains For Locally Delivered Mail option lets you specify what mail will be delivered on this machine. List as many machine names or aliases as are available. For example, the machine may be known as Eastnj officially, but might have aliases such as Turnpike and Somerset. Adding all three will allow mail to be delivered to users at all of those addresses.
By using Masquerade Other Domains, you can have other domains send mail as if they belong to the master domain. This is useful in a situation such as corporate acquisitions, when you want to allow mail to arrive at the old company name, while translating any outgoing mail to the new company name.
The last option in the dialog box provides the ability to directly translate a user address to a standard address. For example, if the company standard is to use an e-mail address such as firstname.lastname@example.org, and the user name is firstname, it would be possible to add a translation from email@example.com, so all of that user's e-mail is addressed properly.
For this article, we won't worry about masquerading. Choose OK to return to the Outgoing Mail screen. The Authentication option relates to the outgoing mail server and is not useful for this example.
Pressing Next brings up the Incoming Mail screen, which shows the options for accepting incoming mail messages. Since we're assuming this machine is the incoming mail server, check Accept Remote SMTP Connections to enable incoming mail.
When you click Finish, a dialog box will be presented for writing the configuration. Choose Continue. YAST will write the configuration to the system and restart the postfix daemon. Choose Quit to leave YAST. The mail system is now configured. It can be tested using the mailx utility from the command line or the KMail utility from the GUI.