DokuWiki » Infrastructure » Operating System » Ubuntu 22.04 LTS

h1. Config postfix smarthost

h2. smarthost with any smtp-server

have a look at: https://www.alldiscoveries.com/configuring-relayhost-smarthost-ubuntu-server-22-04-lts-with-gmail-or-another-email-server-via-postfix/

h2. smarthost with local mailcow-dockerized

currently we are using Ubuntu only as a base for mailcow.

So things are a bit different here, see also: https://docs.mailcow.email/post_installation/firststeps-local_mta/

h3. install postfix and mail

<pre><code class="shell">

sudo apt install mailutils

</code></pre>

h3. configure postfix

<pre><code class="shell">

sudo vim /etc/postfix/master.cf

</code></pre>

<pre>

#smtp      inet  n       -       -       -       -       smtpd

</pre>

<pre><code class="shell">

sudo vim /etc/postfix/main.cf

</code></pre>

<pre>

# as per https://docs.mailcow.email/post_installation/firststeps-local_mta/

relayhost = 172.22.1.1

mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128

inet_interfaces = loopback-only

relay_transport = relay

default_transport = smtp

</pre>

additionally we need to know the server and email-address as well as the password to use

<pre><code class="shell">

vim /etc/postfix/sasl_passwd

</code></pre>

<pre>

mail.example.com:587     mailadr@example.com:password

</pre> 

The above server hostname and port must exactly match the value for "relayhost" in /etc/postfix/main.cf.

Generate a postfix lookup table from the previous file

<pre><code class="shell">

postmap hash:/etc/postfix/sasl_passwd

</code></pre>

Test the lookup table, if all is good then the following will return the specified username:password

<pre><code class="shell">

postmap -q mail.example.com:587 /etc/postfix/sasl_passwd

</code></pre>

next is to bind the local username to the email-address. You may also have a look into @/etc/aliases@ and check who's mail are sent to whom.

<pre><code class="shell">

vim /etc/postfix/canonical

</code></pre>

<pre>

root     mailadr@example.com

</pre> 

The above email-address must exactly match the email-address in sasl_passwd.

Generate a postfix lookup table from the previous file

<pre><code class="shell">

postmap hash:/etc/postfix/canonical

</code></pre>

Make sure that sasl_passwd and sasl_passwd.db files are readable/writeable only by root

<pre><code class="shell">

chmod 600 /etc/postfix/sasl_passwd

chmod 600 /etc/postfix/sasl_passwd.db

</code></pre>

Add postfix to be started at boot

<pre><code class="shell">

systemctl enable postfix

</code></pre>

h4. maybe necessary

<pre><code class="shell">

sudo mkfifo /var/spool/postfix/public/pickup

</code></pre>