This module allows authentication information to be stored in a MySQL database.
When authmysql is installed, a default configuration file,
authmysqlrc will be installed too.  You must edit this file to
set up your MySQL authentication.
NOTE: this authentication module should NOT be used if you are using the
vpopmail virtual mailing list manager. You should select the
authvchkpw authentication module instead (which should happen
automatically). It may be necessary to use the
--without-authmysql flag to the configure script,
because configure by default will include authmysql
if it finds MySQL client libraries..
Edit authmysqlrc, and initialize the following variables:
MYSQL_SERVER - MySQL server name (required).MYSQL_PORT - server port where MySQL accepts
  connections.MYSQL_SOCKET - If MySQL is running on the same machine and
    can accept connections from a filesystem socket, enter the path to the
    filesystem socket here, and do not initialize SERVER/PORT.MYSQL_USERNAME - MySQL username with log in with
    (required).MYSQL_PASSWORD - MySQL password with log in with
    (required).MYSQL_DATABASE - MySQL database to log in to
  (required).MYSQL_USER_TABLE - name of the MySQL with the
    authentication information (see below) (required).MYSQL_LOGIN_FIELD - field that contains the login id for
    this account.MYSQL_CRYPT_PWFIELD - name of the field containing the
    crypt-ed password (either MYSQL_CRYPT_PWFIELD or
    MYSQL_CLEAR_PWFIELD is required). NOTE: this password must
    be crypt-ed using the operating system's crypt function, NOT MySQL's crypt
    function.  MySQL's crypt() function is non-standard and is not generally
    compatible with the operating system's crypt function.MYSQL_CLEAR_PWFIELD - name of the field containing the
    cleartext password (either MYSQL_CRYPT_PWFIELD or
    MYSQL_CLEAR_PWFIELD is required).MYSQL_UID_FIELD - field that contains the system userid for
    this account.MYSQL_GID_FIELD - field that contains the system groupid
    for this account.MYSQL_MAILDIR_FIELD - name of the field containing a
    non-default location of the account's system mailbox (optional).MYSQL_QUOTA_FIELD - name of the field containing a maildir
    quota (optional).DEFAULT_DOMAIN - if the user logs in without specifying
    @domain, use the following domain (in this case the id field
    must always contain user@host) (optional).MYSQL_WHERE_CLAUSE - optional freeform SQL that is appended
    to the SQL query string.The table specified by MYSQL_USER_TABLE should look as follows
(recommended):
CREATE TABLE passwd (
        id                    char(128) DEFAULT '' NOT NULL,
        crypt                 char(128) DEFAULT '' NOT NULL,
        clear                 char(128) DEFAULT '' NOT NULL,
        name                  char(128) DEFAULT '' NOT NULL,
        uid                   int(10) unsigned DEFAULT '65534' NOT NULL,
        gid                   int(10) unsigned DEFAULT '65534' NOT NULL,
        home                  char(255) DEFAULT '' NOT NULL,
        maildir               char(255) DEFAULT '' NOT NULL,
        quota                 char(255) DEFAULT '' NOT NULL,
        KEY id (id(128))
);