[Courier-imap] auth in mysql

[Mohsen P. <mo...@pa...>]

Dear all,
At first i installed qmail from LWQ on Debian.Then i installed
courier-imap & courier-pop & their core.
Then i installed vpopmail with  mysql auth module.Even i tested it & it
read & write to mysql.
Now, When i use following command,i give error:
--------------------------------------------------
localhost:/home/mohsen# telnet 0 110
Trying 0.0.0.0...
Connected to 0.
Escape character is '^]'.
+OK Hello there.
user postmaster@mohsenjan
+OK Password required.
pass 123456
-ERR Login failed.
Connection closed by foreign host.
localhost:/home/mohsen# cd vpopmail-5.4.27
----------------------------------------------
mohsenjan is my domain that i inserted to my db.
When i saw my /var/log/mail.log, i see follow line:
------------------------
Feb 25 19:17:20 localhost authdaemond: SQL query: SELECT pw_name,
pw_passwd, pw_clear_passwd, pw_uid, pw_gid, pw_dir , "", "", "", "" FROM
vpopmail WHERE pw_name = 'postmaster@mohsenjan' 
Feb 25 19:17:20 localhost authdaemond: zero rows returned
Feb 25 19:17:20 localhost authdaemond: no password available to compare
Feb 25 19:17:20 localhost authdaemond: authmysql: REJECT - try next
module
Feb 25 19:17:20 localhost authdaemond: FAIL, all modules rejected
Feb 25 19:18:01 localhost pop3d: LOGOUT, ip=[::ffff:127.0.0.1]
Feb 25 19:18:01 localhost pop3d: Disconnected, ip=[::ffff:127.0.0.1]
-----------------------------------------------
My question: 
How i tell to courier to pw_name is just is my username from email?.It
doesn't contain domain name
I have attached my /etc/courier/authmysqlrc file.
Yours,
Mohsen