I need to use virtual aliases for customers emails to receive emails on forwarded address and send emails from the application from their subdomain to users of the application.

The configuration in Postfix is ok and functional at this moment but the wildcard subdomain is not registered in DNS records. So we cant send emails to users or send emails from users.

The postfix configuration is like this:
1- We create a database to store domains, subdomains and users with destination emails.

CREATE TABLE `virtual_domains` (
`id` int(11) NOT NULL auto_increment,
`name` varchar(50) NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

CREATE TABLE `virtual_users` (
`id` int(11) NOT NULL auto_increment,
`domain_id` int(11) NOT NULL,
`password` varchar(106) NOT NULL,
`email` varchar(100) NOT NULL,
PRIMARY KEY (`id`),
FOREIGN KEY (domain_id) REFERENCES virtual_domains(id) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

CREATE TABLE `virtual_aliases` (
`id` int(11) NOT NULL auto_increment,
`domain_id` int(11) NOT NULL,
`source` varchar(100) NOT NULL,
`destination` varchar(100) NOT NULL,
PRIMARY KEY (`id`),
FOREIGN KEY (domain_id) REFERENCES virtual_domains(id) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

2.- we create 3 files on postfix:

mysql-virtual-domains.cf :
user = postfix_user
password = postfix_password
hosts = 127.0.0.1
dbname = postfix_db
query = SELECT 1 FROM virtual_domains WHERE name='%s'

mysql-virtual-mailboxes.cf :
user = postfix_user
password = postfix_password
hosts = 127.0.0.1
dbname = postfix_db
query = SELECT 1 FROM virtual_users WHERE email='%s'

mysql-virtual-aliases.cf :
user = postfix_user
password = postfix_password
hosts = 127.0.0.1
dbname = postfix_db
query = SELECT destination FROM virtual_aliases WHERE source='%s'

3.- we configure main.cf in postfix to read the emails and destination.

virtual_mailbox_domains = mysql:/etc/postfix/mysql-virtual-domains.cf
virtual_mailbox_maps = mysql:/etc/postfix/mysql-virtual-mailboxes.cf
virtual_alias_maps = mysql:/etc/postfix/mysql-virtual-aliases.cf

Now we need to have the dns MX connection to send and receive emails from user@subdomain.domain.com

It would be a greet idea to implement this as a wildcard email processing system.

Thanks for reading and maybe implement this as soon as possible.

Best regards

Hi,
I run a mail server using plesk and have several users. I would propose to use wildcards in email aliases. This is especially interesting if you want to register to each service with another email adress.
Example:
Any email, which goes to somerandomchars_a@mydomain.com ends up in my wife's inbox.
Any email looking like somerandomchars_j@mydomain.com end up in my inbox.
So my alias should be looking like:
*_a@mydomain.com -> wife@mydomain.com and
*_j@mydomain.com -> husband@mydomain.com.
Everything else goes via catchall to postmaster@mydomain.com anyways, if not caught by any other email adress or alias.
This would make things a LOT easier!
Thanks.