Quick Postfix Virtual Hosts Configuration

There is 3 main files that need to be modifiy:

    * /etc/mailname : the visible mail name of the system
    * /etc/aliases : Postfix local alias database format
    * /etc/postfix/main.cf : Postfix configuration parameters

/etc/mailname : This is where you set the domain name of the system, has seen by the other. It needs, in most cases, to look like a real domain name, otherwise, the next smtp server on the road might refuse the mails originating from your machine.

In this example, I choose hell.com.

/etc/aliases :
The place you define aliases. For instance, it is quite good to redirect all mail to root to your normal user.

Here:

    # Added by installer for initial user
    root: myuser

    From now on, you will be able to get system notice using mutt with your myuser user.

/etc/postfix/main.cf :

The place we are going to make a few changes. Let’s say I want to be able to relay mail sent to user at mydomain.org to my personnal adress nik@foo.bar.

In the first place I need to define a virtual alias domain.

    virtual_alias_domains = mydomain.org

Then, we need to tell postfix where the alias database is:

    virtual_alias_maps = hash:/etc/postfix/virtual

Adding those 2 lines is sufficient to make your box treat the mail sent to linux.org. Now, we need to tell postfix what to do with the mails.

Create and Edit the file /etc/postfix/virtual and add:

    nik@mydomain.org nikfoobar.org
    localuser@mydomain.org myuser
    @mydomain.org catch-all@foobar.org

At the first line, we say that we want all the mail to nik@mydomain.org to be forwarded to nik@foobar.org.
On the second line we tell postfix to deliver the mails to localuser@mydomain.org to the Unix user myuser.
On line 3, we define a catch-all adress which will forward any mails to mail account to the mail account catch-all@foobar.org.

This is it!

Now we need to regenerate the aliases database as well as the virtual mail aliases dataase. To do so, execute the following commands:

    root@laptop:~#newaliases
    root@laptop:~#postmap /etc/postfix/virtual

And restart postfix:

    root@laptop:~#/etc/init.d/postfix

And you are done Smiling.