POSTFIX MTA IN REDHAT LINUX

POSTFIX MTA

Features:

1. Message Transfer Agent (MTA)

2. Modular (SpamAssAssin)

3. Drop-in replacement for Sendmail, as it provides a 'sendmail' binary

Note: Use 'system-switch-mail*' package to switch between Postfix and Sendmail

Tasks:
1. Install Postfix
•yum -y install postfix

/etc/postfix - primary configuration directory

/etc/postfix/main.cf - primary configuration file

/etc/postfix/transport - contains routing rules for domains

/etc/postfix/virtual - contains virtual user mappings

2. Install 'system-switch-mail' package
•yum -y install system-switch-mail

3. Switch default MTA from Sendmail, to Postfix

•system-switch-mail

Note: The default Postfix configuration binds to 127.0.0.1:25

4. Test local mail delivery

•Use 'mutt' to test local delivery

5. Configure Postfix to receive messages from remote systems

•set: inet_interfaces=all

•set mydestinations = linuxcbt.internal

•service postfix restart

•Confirm directives using: 'postconf'

•Attempt to send message from LINUXCBTSERV1 -> LINUXCBTSERV4

•If it fails, configure MTA on LINUXCBTSERV1 to listen to routable IP

• update /etc/mail/sendmail.mc

• make all -C /etc/mail

•service sendmail restart

Note: Ensure that 'sendmail-cf*' package is installed, in order to updated .mc files to .cf files