Getting virtual accounts to work in courier wasn't easy, but here's my solution. I got some help from Sam (Thanks!) and did a lot of poking and experimenting in authmysqlrc. There's a special problem with some mail clients, such as Eudora, which store POP account information in the format user@pop_host and have difficulty with user account names containing "@", which is the simplest situation with virtual accounts. An POP host spec in Eudora of "user@domain@mailhost" gets parsed as user "user", mail host "domain@mailhost" rather than user "user@domain", mail host "mailhost".

I used a mysql courier.passwd table with the following structure:

+-------------+------------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-------------+------------------+------+-----+---------+-------+ | id | char(128) | | MUL | | | | crypt | char(128) | | | | | | clear | char(128) | | | | | | name | char(128) | | | | | | uid | int(10) unsigned | | | 65534 | | | gid | int(10) unsigned | | | 65534 | | | home | char(255) | | | | | | maildir | char(255) | | | | | | quota | char(255) | | | | | | domain_name | char(60) | | | fmp.com | | +-------------+------------------+------+-----+---------+-------+

I set up hosteddomains to include all domains for virtual accounts.

Make sure that in authmysqlrc you have DEFAULT_DOMAIN set to something. Anything will do, otherwise mysql queries on bare ID's will fail in MYSQL_SELECT_CLAUSE and authdaemon will return "Service temporarily unavailable" and not fall through if you have chaining authentication modules.

Set MYSQL_SELECT_CLAUSE to:

select id,crypt,uid,gid,clear,home,maildir,quota,name from courier.passwd where (id="$(local_part)" and domain_name="$(domain)") or CONCAT(id, "%", domain_name)="$(local_part)"

(all one line)

User ID's for virtual accounts are stored without a domain name.

If the database contains an id "friend" with a domain_name of "frobniz.com", an esmpt "rcpt_to: <fri...@frobniz.com>" will find the appropriate virtual account and allow incoming email. Authmysql will _also_ authenticate "friend%frobniz.com" for the purpose of POP3 logins, which allows Eudora to see the account. As a side effect, mail to "frie...@frobniz.com" will also be delivered, but I don't thing this is cause for concern.