ดูต้นฉบับสำหรับ Upgrade installation 3

Info:

* You need to have at least a base installation
* MySQL does not work for Virtual Domains, the domain and user returns as garbled text in authentication.
* Virtual Alias Domain is used instead (it works).
* This should work for Ubuntu, Centos and Freebsd

<syntaxhighlight lang="bash">
sudo postconf "virtual_alias_domains = yourdomain1.com yourdomain2.com yourdomain3.com youretc.com โดเมนคุณ.ไทย"
sudo postconf "virtual_alias_maps = hash:/etc/postfix/virtual"
</syntaxhighlight >

edit or create  '''/etc/postfix/virtual'''
<syntaxhighlight lang="bash">
yourdomain1.com                     DOMAIN
someuser@yourdomain1.com            user1

yourdomain2.com                     DOMAIN
anotheruser@yourdomain2.com         user2

yourdomain3.com                     DOMAIN
admin@yourdomain3.com               user3

youretc.com                         DOMAIN
admin@youretc.com                   user1

โดเมนคุณ.ไทย                        DOMAIN
แอดมิน@โดเมนคุณ.ไทย                  user1
</syntaxhighlight >

Update your changes
<syntaxhighlight lang="bash">
sudo postmap /etc/postfix/virtual
</syntaxhighlight >