TABLE_MYSQL(5) - File Formats Manual

table_mysql - format description for smtpd MySQL or MariaDB tables

This manual page documents the file format of MySQL or MariaDB tables used by the smtpd(8) mail daemon.

The format described here applies to tables as defined in smtpd.conf(5).

A mysql table allows the storing of usernames, passwords, aliases, and domains in a format that is shareable across various machines that support mysql(1).

The table is used by smtpd(8) when authenticating a user, when user information such as user-id and/or home directory is required for a delivery, when a domain lookup may be required, and/or when looking for an alias.

A MySQL table consists of one or more mysql(1) databases with one or more tables.

If the table is used for authentication, the password should be encrypted using the crypt(3) function. Such passwords can be generated using the encrypt(1) utility or smtpctl(8) encrypt command.

The following configuration options are available:

host hostname

This is the host running MySQL or MariaDB. For example:

host db.example.com

username username

The username required to talk to the MySQL or MariaDB database. For example:

username maildba

password password

The password required to talk to the MySQL or MariaDB database. For example:

password OpenSMTPDRules!

database databse

The name of the MySQL or MariaDB database. For example:

databse opensmtpdb

query_alias SQL statement

This is used to provide a query to look up aliases. The question mark is replaced with the appropriate data. For alias it is the left hand side of the SMTP address. This expects one VARCHAR to be returned with the user name the alias resolves to.

query_credentials SQL statement

This is used to provide a query for looking up user credentials. The question mark is replaced with the appropriate data. For credentials it is the left hand side of the SMTP address. The query expects that there are two VARCHARS returned, one with a user name and one with a password in crypt(3) format.

query_domain SQL statement

This is used to provide a query for looking up a domain. The question mark is replaced with the appropriate data. For the domain it would be the right hand side of the SMTP address. This expects one VARCHAR to be returned with a matching domain name.

query_mailaddrmap SQL statement

This is used to provide a query to look up senders. The question mark is replaced with the appropriate data. This expects one VARCHAR to be returned with the address the sender is allowed to send mails from.

A generic SQL statement would be something like:

query_ SELECT value FROM table WHERE key=?;

Example based on the OpenSMTPD FAQ: Building a Mail Server The filtering part is excluded in this example.

The configuration below is for a medium-size mail server which handles multiple domains with multiple virtual users and is based on several assumptions. One is that a single system user named vmail is used for all virtual users. This user needs to be created:

# useradd -g =uid -c "Virtual Mail" -d /var/vmail -s /sbin/nologin vmail
# mkdir /var/vmail
# chown vmail:vmail /var/vmail

MySQL schema

CREATE TABLE domains (
  id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
  domain VARCHAR(255) NOT NULL DEFAULT ''
);
CREATE TABLE virtuals (
    id INT AUTO_INCREMENT PRIMARY KEY,
    email VARCHAR(255) NOT NULL DEFAULT '',
    destination VARCHAR(255) NOT NULL DEFAULT ''
);
CREATE TABLE credentials (
    id INT AUTO_INCREMENT PRIMARY KEY,
    email VARCHAR(255) NOT NULL DEFAULT '',
    password VARCHAR(255) NOT NULL DEFAULT ''
);
INSERT INTO domains VALUES (1, "example.com");
INSERT INTO domains VALUES (2, "example.net");
INSERT INTO domains VALUES (3, "example.org");

INSERT INTO virtuals VALUES (1, "[email protected]", "[email protected]");
INSERT INTO virtuals VALUES (2, "[email protected]", "[email protected]");
INSERT INTO virtuals VALUES (3, "[email protected]", "[email protected]");
INSERT INTO virtuals VALUES (4, "[email protected]", "vmail");
INSERT INTO virtuals VALUES (5, "[email protected]", "[email protected]");
INSERT INTO virtuals VALUES (6, "[email protected]", "[email protected]");
INSERT INTO virtuals VALUES (7, "[email protected]", "[email protected]");
INSERT INTO virtuals VALUES (8, "[email protected]", "vmail");

INSERT INTO credentials VALUES (1, "[email protected]", "$2b$08$ANGFKBL.BnDLL0bUl7I6aumTCLRJSQluSQLuueWRG.xceworWrUIu");
INSERT INTO credentials VALUES (2, "[email protected]", "$2b$08$AkHdB37kaj2NEoTcISHSYOCEBA5vyW1RcD8H1HG.XX0P/G1KIYwii");

/etc/mail/mysql.conf

host db.example.com
username maildba
password OpenSMTPDRules!
database opensmtpdb
query_alias SELECT destination FROM virtuals WHERE email=?;
query_credentials SELECT email, password FROM credentials WHERE email=?;
query_domain SELECT domain FROM domains WHERE domain=?;

/etc/mail/smtpd.conf

table domains mysql:/etc/mail/mysql.conf
table virtuals mysql:/etc/mail/mysql.conf
table credentials mysql:/etc/mail/mysql.conf
listen on egress port 25 tls pki mail.example.com
listen on egress port 587 tls-require pki mail.example.com auth <credentials>
accept from any for domain <domains> virtual <virtuals> deliver to mbox

/etc/mail/mysql.conf

host db.example.com
username postfix
password PostfixOutOpenSMTPDin
database postfix
query_alias SELECT destination FROM alias WHERE email=?;
query_credentials SELECT username, password FROM mailbox WHERE username=?;
query_domain SELECT domain FROM domain WHERE domain=?;

The rest of the config remains the same.

/etc/mail/mysql.conf

Default table-mysql(8) configuration file.

Documenting the following query options:

**query_netaddr**
**query_userinfo**
**query_source**
**query_mailaddr**
**query_addrname**

smtpd.conf(5), smtpctl(8), smtpd(8), encrypt(1), crypt(3)

OpenBSD 7.5 - July 4, 2016