Postfix mail config file

Lines 2, Request that intranet mail is delivered directly, and that external mail is given to a gateway. Line 5: This prevents mail from being stuck in the queue when the machine is turned off. Postfix tries to deliver mail directly, and gives undeliverable mail to a gateway.

This section presents additional configuration. Important notes: Do not list the. Do not list the. Lines Forward mail from the Internet for "the.

Line This is a must if Postfix receives mail via a NAT relay or proxy that presents a different IP address to the world than the local machine. Lines Define the list of valid addresses in the "the. This section applies to dialup connections that are down most of the time. For dialup connections that are up 24x7, see the local area network section above.

If you do not have your own hostname and IP address usually with dialup, cable TV or DSL connections then you should also study the section on " Postfix on hosts without a real Internet hostname ". If your machine is disconnected most of the time, there isn't a lot of opportunity for Postfix to deliver mail to hard-to-reach corners of the Internet. It's better to give the mail to a machine that is connected all the time.

Normally, Postfix attempts to deliver outbound mail at its convenience. If your machine uses on-demand dialup IP, this causes your system to place a telephone call whenever you submit new mail, and whenever Postfix retries to deliver delayed mail.

To prevent such telephone calls from being placed, disable spontaneous SMTP mail deliveries. The exact location of the Postfix sendmail command is system-specific. If you have disabled spontaneous SMTP mail delivery , you also need to run the " sendmail -q " command every now and then while the dialup link is up, so that newly-posted mail is flushed from the queue.

This section is for hosts that don't have their own Internet hostname. Postfix will let you send and receive mail just fine between accounts on a machine with a fantasy name. However, you cannot use a fantasy hostname in your email address when sending mail into the Internet, because no-one would be able to reply to your mail. In fact, more and more sites refuse mail addresses with non-existent domain names. Note: the following information is Postfix version dependent.

Postfix 2. This mapping happens ONLY when mail leaves the machine; not when you send mail between users on the same machine. The solution with older Postfix systems is to use valid Internet addresses where possible, and to let Postfix map valid Internet addresses to local fantasy addresses. With this, you can send mail to the Internet and to local fantasy addresses, including mail to local fantasy addresses that don't have a valid Internet address of their own.

Lines Substitute your fantasy hostname here. Do not use a domain name that is already in use by real organizations on the Internet. See RFC for examples of domain names that are guaranteed not to be owned by anyone.

Lines 5, 9, This provides the mapping from "your-login-name hostname. Last updated 10 months ago. Help improve this document in the forum. Server Overview Hyperscale Docs. Note This guide does not cover setting up Postfix Virtual Domains , for information on Virtual Domains and other advanced configurations see References. Installation To install Postfix run the following command: sudo apt install postfix For now, it is ok to simply accept defaults by pressing return for each question. On each screen, select the following values: Internet Site mail.

Run the following command to restart the postfix daemon: sudo systemctl restart postfix. It's typically used by dovecot-lda, doveadm, possibly imap process, etc. Its default permissions make it readable only by root, but you may need to relax these permissions. Users that have access to this socket are able to get a list of all usernames and get results of everyone's userdb lookups. Now it is time to test the setup. Escaping chroot The Ubuntu Postfix package will by default install into a chroot environment for security reasons.

For example, edit the smtp entry: smtp unix - - - - - smtp -v Then, reload the service as usual: sudo systemctl reload postfix. References Administering a Postfix server can be a very complicated task. The Postfix website documents all available configuration options. The Ubuntu Wiki Postfix page has more information from a Ubuntu context. Info on how to set up mailman3 with postfix Last updated 10 months ago.

End-to-End Multicloud Solutions. Solving Together. After you have installed Postfix, you can work with settings in the main. Note: This article assumes that you are using a single domain for your email needs. One of the key aspects of Postfix is that it is designed to be a modular package. You can begin to see the modular nature of Postfix when you look at the main. Many settings refer to other files on the server. This setup can seem slightly confusing at first, and your initial reaction might be to hard code the data rather than reference another file with a single word in it.

However, we recommend retaining the modularity of Postfix and editing multiple files for what might seem like simple settings. Such modularity will be useful when you start adding multiple domains, users, and aliases to your setup.

The file consists of basically three sections. The second section has settings for TLS parameters. This article focuses on the last section, which looks as follows on the democloud server:. Note : Some of the settings already have the host name from the base Postfix installation. Although some of the settings might be self-explanatory, the following sections describe them so that you can get a better understanding of Postfix and what you can do with it.

The myhostname value was set during the Postfix installation when you entered the domain name that you want to use. This name also matches the cloud server host name.