Change 2 files (mysql-virtual_mailboxes.cf and authmysqlrc) to Maildir work.
mail:/etc/postfix# more mysql-virtual_mailboxes.cf
user = postfix password = postfix dbname = postfix query = SELECT CONCAT(SUBSTRING_INDEX(email,'@',-1),'/','',SUBSTRING_INDEX(email,'@',1),'/','Maildir/') FROM users WHERE email='%s' hosts = 127.0.0.1
mail:/etc/courier# more authmysqlrc
MYSQL_SERVER localhost MYSQL_USERNAME postfix MYSQL_PASSWORD postfix MYSQL_PORT 0 MYSQL_DATABASE postfix MYSQL_USER_TABLE users MYSQL_CRYPT_PWFIELD password #MYSQL_CLEAR_PWFIELD password MYSQL_UID_FIELD 5000 MYSQL_GID_FIELD 5000 MYSQL_LOGIN_FIELD email MYSQL_HOME_FIELD "/home/vmail" MYSQL_MAILDIR_FIELD CONCAT(SUBSTRING_INDEX(email,'@',-1),'/','',SUBSTRING_INDEX(email,'@',1),'/','Maildir/') #MYSQL_NAME_FIELD MYSQL_QUOTA_FIELD quota
Now you can receive and get!