Mail Servers

Mail transfer agents (MTAs) are servers that are used to receive local e-mail and send outgoing e-mail.

Postfix

Configuration options:

  • myhostname = The hostname of the mail server.

    • Default: If a fully qualified domain name (FQDN) is configured on the Unix machine then Postfix will use that.

  • mynetworks = Define the networks that are allowed to send e-mails.

    • Default: 127.0.0.0/8

  • mydestination = Define allowed destinations for e-mails.

    • Default: $myhostname localhost.$mydomain localhost

  • relayhost = Define the server to forward mail to. [1]

Null Client Configuration

In a null client configuration, mail is not accepted by the mail server. It only forwards local e-mails to another MTA.

Example - Forward all e-mails from the localhost to the server at the 10.0.0.1 address.

myhostname = server.rootpages.tld
mydomain = rootpages.tld
myorigin = $mydomain
inet_interfaces = loopback-only
mydestination =
relayhost = 10.0.0.1

Gateway Configuration

In a gateway-client setup, mail is forwarded from the one or more specified networks to another MTA.

Example - Forward all e-mails from localhost and from the 10.0.0.0/24 network to the 10.0.0.1 server.

myhostname = server.example.com
mydomain = example.com
myorigin = $mydomain
inet_interfaces = all
mydestination = $myhostname localhost.$mydomain localhost $mydomain
mynetworks = 10.0.0.0/24 127.0.0.0/8
relayhost = 10.0.0.1

[2][3]

History

Bibliography

  1. “Postfix Basic Configuration.” Postfix. Accessed October 1, 2016. http://www.postfix.org/BASIC_CONFIGURATION_README.html

  2. “Postfix Standard Configuration.” Postfix. Accessed October 1, 2016. http://www.postfix.org/STANDARD_CONFIGURATION_README.html

  3. “Configure a system to forward all email to a central mail server.” CertDepot. November 25, 2015. Accessed October 1, 2016. https://www.certdepot.net/rhel7-configure-system-forward-email-central-mail-server/