Networking System Administration

Sendmail Configuration

Sendmail is the default MTA on the RedHat Linux distribution. Do NOT use linuxconf to configure sendmail as it has NOT been updated to work with current versions of sendmail!!! (The tool linuxconf is no longer included with current versions of Red Hat Linux 7.3+)
RPM packages required: sendmail, sendmail-cf and m4
Ubuntu/Debian install: sudo apt-get sendmail sendmail-base sendmail-bin sendmail-cf mailutils
Sendmail receives mail for local system user login accounts. Mail is held in a single file: /var/mail/userID
Steps to run mail server using sendmail: 1. Required for inbound mail: The mail server must be identified by the DNS as the mail server in order to receive mail. See the YoLinux web tutorial on configuring DNS. 2. /etc/mail/local-host-names (Required) (Red Hat 7.1 - Fedora Core 3)
/etc/sendmail.cw (Red Hat 6.x)

SMTP in Linux

The procedure to configure email options for SMTP on the UNIX system and Linux varies depending on whether your environment has a single Rational ClearQuest Server or multiple servers. Use the appropriate procedure for your environment.
When you use SMTP on the UNIX system and Linux, all email notification messages that Rational ClearQuest Web sends have the From address of the user who set up the email rules and a Reply To address that corresponds to the SMTP Reply To address specified on the E-Mail Options tab of the Site Administration page
Procedure:
1. Log on to the Rational ClearQuest Web client by using an account with the Super User privilege. 2. Configure the E-mail Options tab of the Site Administration page: a. In the Sending E-mail Status list, select Active or Inactive, as appropriate. b. In the Mail Transport Type list, select SMTP. c. In the SMTP Host field, enter the name of your SMTP server. d. In the SMTP Reply To field, enter the address of a dedicated email account that Rational ClearQuest Web can use as the Reply To address in notification messages. Use the following format: SomeGenericReturnAddress@MyDomain.

Dovecot

Dovecot is a Mail Delivery Agent, written with security primarily in mind. It supports the major mailbox formats: mbox or Maildir. This section explain how to set it up as an imap or pop3 server.
To configure dovecot, you can edit the file /etc/dovecot/dovecot.conf. You can choose the protocol you use. It could be pop3, pop3s (pop3 secure), imap and imaps (imap secure). A description of these protocols is beyond the scope of this guide. For further information, refer to the Wikipedia articles on POP3 and IMAP.
IMAPS and POP3S are more secure that the simple IMAP and POP3 because they use SSL encryption to connect. Once you have chosen the protocol, amend the following line in the file /etc/dovecot/dovecot.conf:

Email Servers in Linux

Internet mail is broken down into three basic parts: 1. MTA or Mail Transfer Agents - sendmail, qmail, etc - Links/Info * Postfix email server configuration * Sendmail email server configuration 2. Mail Retrieval Software - pop3, imap, etc - Links/Info 3. Mail User Agent (MUA): E-Mail client - Netscape, MUTT, etc - Links/Info

Internet mail is sent from the email client to the email server which routes it to the intended destination which will also be an email server. The protocol by which the email servers communicate is called SMTP (Simple Mail Transfer Protocol) and the email server software is known as the MTA or Mail Transfer Agent. This page lists the popular MTA eMail server programs used, as well as supporting programs such as email list servers and spam filters. Also listed are the RFC 's (Request For Comments) on which the internet email standards are currently or eventually based.

Fedora 15 email server

Email was born in the 1960s. The mailbox was a file in a user 's home directory that was readable only by that user. Primitive mail applications appended new text messages to the bottom of the file, making the user wade through the constantly growing file to find any particular message. This system was only capable of sending messages to users on the same system.
The first network transfer of an electronic mail message file took place in 1971 when a computer engineer named Ray Tomlinson sent a test message between two machines via ARPANET—the precursor to the Internet. Communication via email soon became very popular, comprising 75 percent of ARPANET 's traffic in less than two years.
Today, email systems based on standardized network protocols have evolved into some of the most widely used services on the Internet. Fedora offers many advanced applications to serve and access email.

Links: Info Internet mail is sent from the email client to the email server which routes it to the intended destination which will also be an email server. The protocol by which the email servers communicate is called SMTP (Simple Mail Transfer Protocol) and the email server software is known as the MTA or Mail Transfer Agent. This page lists the popular MTA eMail server programs used, as well as supporting programs such as email list servers and spam filters. Also listed are the RFC 's (Request For Comments) on which the internet email standards are currently or eventually based. Fedora 15 email server Email was born in the 1960s. The mailbox was a file in a user 's home directory that was readable only by that user. Primitive mail applications appended new text messages to the bottom of the file, making the user wade through the constantly growing file to find any particular message. This system was only capable of sending messages to users on the same system. The first network transfer of an electronic mail message file took place in 1971 when a computer engineer named Ray Tomlinson sent a test message between two machines via ARPANET—the precursor to the Internet. Communication via email soon became very popular, comprising 75 percent of ARPANET 's traffic in less than two years. Today, email systems based on standardized network protocols have evolved into some of the most widely used services on the Internet. Fedora offers many advanced applications to serve and access email.