gitlab-org--gitlab-foss/doc/administration/reply_by_email_postfix_setup.md

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---
stage: Enablement
group: Distribution
info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments
---
# Set up Postfix for incoming email **(FREE SELF)**
This document will take you through the steps of setting up a basic Postfix mail
server with IMAP authentication on Ubuntu, to be used with [incoming email](incoming_email.md).
The instructions make the assumption that you are using the email address `incoming@gitlab.example.com`, that is, username `incoming` on host `gitlab.example.com`. Don't forget to change it to your actual host when executing the example code snippets.
## Configure your server firewall
1. Open up port 25 on your server so that people can send email into the server over SMTP.
1. If the mail server is different from the server running GitLab, open up port 143 on your server so that GitLab can read email from the server over IMAP.
## Install packages
1. Install the `postfix` package if it is not installed already:
```shell
sudo apt-get install postfix
```
When asked about the environment, select 'Internet Site'. When asked to confirm the hostname, make sure it matches `gitlab.example.com`.
1. Install the `mailutils` package.
```shell
sudo apt-get install mailutils
```
## Create user
1. Create a user for incoming email.
```shell
sudo useradd -m -s /bin/bash incoming
```
1. Set a password for this user.
```shell
sudo passwd incoming
```
Be sure not to forget this, you'll need it later.
## Test the out-of-the-box setup
1. Connect to the local SMTP server:
```shell
telnet localhost 25
```
You should see a prompt like this:
```shell
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
220 gitlab.example.com ESMTP Postfix (Ubuntu)
```
If you get a `Connection refused` error instead, verify that `postfix` is running:
```shell
sudo postfix status
```
If it is not, start it:
```shell
sudo postfix start
```
1. Send the new `incoming` user an email to test SMTP, by entering the following into the SMTP prompt:
```plaintext
ehlo localhost
mail from: root@localhost
rcpt to: incoming@localhost
data
Subject: Re: Some issue
Sounds good!
.
quit
```
NOTE:
The `.` is a literal period on its own line.
If you receive an error after entering `rcpt to: incoming@localhost`
then your Postfix `my_network` configuration is not correct. The error will
say 'Temporary lookup failure'. See
[Configure Postfix to receive email from the Internet](#configure-postfix-to-receive-email-from-the-internet)._
1. Check if the `incoming` user received the email:
```shell
su - incoming
mail
```
You should see output like this:
```plaintext
"/var/mail/incoming": 1 message 1 unread
>U 1 root@localhost 59/2842 Re: Some issue
```
Quit the mail app:
```shell
q
```
1. Sign out of the `incoming` account, and go back to being `root`:
```shell
logout
```
## Configure Postfix to use Maildir-style mailboxes
Courier, which we install later to add IMAP authentication, requires mailboxes to have the Maildir format, rather than mbox.
1. Configure Postfix to use Maildir-style mailboxes:
```shell
sudo postconf -e "home_mailbox = Maildir/"
```
1. Restart Postfix:
```shell
sudo /etc/init.d/postfix restart
```
1. Test the new setup:
1. Follow steps 1 and 2 of _[Test the out-of-the-box setup](#test-the-out-of-the-box-setup)_.
1. Check if the `incoming` user received the email:
```shell
su - incoming
MAIL=/home/incoming/Maildir
mail
```
You should see output like this:
```plaintext
"/home/incoming/Maildir": 1 message 1 unread
>U 1 root@localhost 59/2842 Re: Some issue
```
Quit the mail app:
```shell
q
```
If `mail` returns an error `Maildir: Is a directory` then your
version of `mail` doesn't support Maildir style mailboxes. Install
`heirloom-mailx` by running `sudo apt-get install heirloom-mailx`. Then,
try the above steps again, substituting `heirloom-mailx` for the `mail`
command.
1. Sign out of the `incoming` account, and go back to being `root`:
```shell
logout
```
## Install the Courier IMAP server
1. Install the `courier-imap` package:
```shell
sudo apt-get install courier-imap
```
2018-03-02 06:32:39 -05:00
And start `imapd`:
```shell
imapd start
```
2018-03-02 06:32:39 -05:00
1. The `courier-authdaemon` isn't started after installation. Without it, IMAP authentication fails:
```shell
sudo service courier-authdaemon start
```
You can also configure `courier-authdaemon` to start on boot:
```shell
sudo systemctl enable courier-authdaemon
```
## Configure Postfix to receive email from the internet
1. Let Postfix know about the domains that it should consider local:
```shell
sudo postconf -e "mydestination = gitlab.example.com, localhost.localdomain, localhost"
```
1. Let Postfix know about the IPs that it should consider part of the LAN:
Let's assume `192.168.1.0/24` is your local LAN. You can safely skip this step if you don't have other machines in the same local network.
```shell
sudo postconf -e "mynetworks = 127.0.0.0/8, 192.168.1.0/24"
```
1. Configure Postfix to receive mail on all interfaces, which includes the internet:
```shell
sudo postconf -e "inet_interfaces = all"
```
1. Configure Postfix to use the `+` delimiter for sub-addressing:
```shell
sudo postconf -e "recipient_delimiter = +"
```
1. Restart Postfix:
```shell
sudo service postfix restart
```
## Test the final setup
1. Test SMTP under the new setup:
1. Connect to the SMTP server:
```shell
telnet gitlab.example.com 25
```
You should see a prompt like this:
```shell
Trying 123.123.123.123...
Connected to gitlab.example.com.
Escape character is '^]'.
220 gitlab.example.com ESMTP Postfix (Ubuntu)
```
If you get a `Connection refused` error instead, make sure your firewall is set up to allow inbound traffic on port 25.
1. Send the `incoming` user an email to test SMTP, by entering the following into the SMTP prompt:
```plaintext
ehlo gitlab.example.com
mail from: root@gitlab.example.com
rcpt to: incoming@gitlab.example.com
data
Subject: Re: Some issue
Sounds good!
.
quit
```
NOTE:
The `.` is a literal period on its own line.
1. Check if the `incoming` user received the email:
```shell
su - incoming
MAIL=/home/incoming/Maildir
mail
```
You should see output like this:
```plaintext
"/home/incoming/Maildir": 1 message 1 unread
>U 1 root@gitlab.example.com 59/2842 Re: Some issue
```
Quit the mail app:
```shell
q
```
1. Sign out of the `incoming` account, and go back to being `root`:
```shell
logout
```
1. Test IMAP under the new setup:
1. Connect to the IMAP server:
```shell
telnet gitlab.example.com 143
```
You should see a prompt like this:
```shell
Trying 123.123.123.123...
Connected to mail.gitlab.example.com.
Escape character is '^]'.
- OK [CAPABILITY IMAP4rev1 UIDPLUS CHILDREN NAMESPACE THREAD=ORDEREDSUBJECT THREAD=REFERENCES SORT QUOTA IDLE ACL ACL2=UNION] Courier-IMAP ready. Copyright 1998-2011 Double Precision, Inc. See COPYING for distribution information.
```
1. Sign in as the `incoming` user to test IMAP, by entering the following into the IMAP prompt:
```plaintext
a login incoming PASSWORD
```
Replace PASSWORD with the password you set on the `incoming` user earlier.
You should see output like this:
```plaintext
a OK LOGIN Ok.
```
1. Disconnect from the IMAP server:
```shell
a logout
```
## Done
If all the tests were successful, Postfix is all set up and ready to receive email! Continue with the [incoming email](incoming_email.md) guide to configure GitLab.
---
_This document was adapted from <https://help.ubuntu.com/community/PostfixBasicSetupHowto>, by contributors to the Ubuntu documentation wiki._