View source for Setting up postfix with virtual domains

= Postfix on 1.9 =

== General ==
The idea is to create a postfix config to host multiple maildomains.<BR>
I want to document both how it's set up and how it's maintained

When you are done with postfix installation you could proceed and install (depending on your needs)
* clamav
* gross
* dovecot
* Other email related applications
Have a look at [[Hosting_services_on_Alpine#Mail]] for various alternatives

== Initial Setup ==
Burn [http://dl-3.alpinelinux.org/alpine/v1.9/iso/alpine-1.9.0_alpha10-i386.iso alpine_1.9alpha10] on a CD and boot the machine.<BR>
'''''Suggestion:''' Follow notes on [[Setting_up_a_ssh-server]] to be able to remotely administer this box.''

== Postfix ==

=== Install ===
 apk_add postfix

=== Prepare ===
We need to create a user on this system that has rights to read/write mail on you system.<BR>
Let's call this user ''vmail'' (you can choose another name if you like).<BR>
You will get prompted for a password.
 adduser vmail
Now we need to know what gid/uid that user got.<BR>
Take notes on the numbers, you will need the in the upcoming configuration (in my case I got uid/gid '1001').
 grep vmail /etc/passwd
This newly-created user will need permissions in the ''mail'' group.<BR>
Edit ''/etc/group'' and add ''vmail'' to the ''postdrop'' group. Se example below:
<pre>
postdrop:x:208:vmail
</pre>

==== Create missing dirs ====
Seems we are missing ''/var/spool/mail'' and ''/var/mail'' so we need to create those
 mkdir /var/spool/mail
 ln -s /var/spool/mail /var/mail

==== Create virtual maildir ====
In the upcoming configuration we are going to specify ''/var/mail/vhosts/'' as the ''virtual_mailbox_base'' so we need to create it.
 mkdir /var/mail/vhosts
And we need to give permissions to our ''vmail'' user so he can read/write in this folder.
 chown vmail:vmail /var/mail/vhosts

=== Configuration ===
For now I just dump whatever I have.
I will clean up these notes soon.

==== /etc/postfix/main.cf ====
These are the variables that varies from the defaults
<pre>
## These settings differers from the default config ##
soft_bounce = yes   # For testing
myhostname = mail.example.net
mydomain = example.net
myorigin = $mydomain
mydestination = localhost, mail.localdomain, localhost.localdomain, localdomain   # See 'virtual_mailbox_domains' for more information
mynetworks = 192.168.10.0/24, 127.0.0.0/8
relayhost =
in_flow_delay = 1s
home_mailbox = Maildir/
mail_spool_directory = /var/spool/mail
smtpd_banner = $myhostname ESMTP $mail_name ($mail_version)

## The following is added to the config ##
virtual_mailbox_domains = example.net
virtual_mailbox_base = /var/mail/vhosts
virtual_mailbox_maps = hash:/etc/postfix/vmailbox
virtual_minimum_uid = 100
virtual_uid_maps = static:1001
virtual_gid_maps = static:1001
virtual_alias_maps = hash:/etc/postfix/valias
</pre>

==== /etc/postfix/valias ==== 
<pre>
postmaster@example.net user1@example.net
hostmaster@example.net user2@example.net
</pre>

==== /etc/postfix/vmailbox ==== 
<pre>
user1@example.net      example.net/user1/
user2@example.net      example.net/user2/
@example.net           example.net/catchall #everyone else doesn't match rule above
</pre>

=== Create DB's ===
Once you created the above config-files, you need to make generate some DB's
 postmap /etc/postfix/vmailbox
 postmap /etc/postfix/valias
I am not 100% if the next command is needed, but I ''think'' that you need to create the 'aliases' DB.
 postmap /etc/postfix/aliases

=== Start postfix ===
It's time to start. Hopefully it works!
 /etc/init.d/postfix start

=== Debugging ===
In case something goes wrong you should have a look in your syslog.<BR>
Personally I use to tail the logfile while debugging
 tail -f /var/log/messages