[Dovecot] Domain variable in checkpassword

[sawyer x]

Hello everyone

I'm using the checkpassword method but I don't get the domain a user inputs.
I can't cross check per virtual domains if I'm not getting one, which means
it renders all my efforts useless.

I've tried sending %d as a variable to my checkpassword script, but I'm just
getting %d instead.
This is a dump of my information:

%ENV = {
          'USERNAME_TRANSLATION' => '',
          'SYSLOG_FACILITY' => '16',
          'CACHE_SIZE' => '0',
          'RESTRICT_GID_LAST' => '',
          'TCPREMOTEIP' => '213.31.43.3',
          'RESTRICT_GID_FIRST' => '',
          'AUTH_NAME' => 'default',
          'CACHE_TTL' => '3600',
          'SERVICE' => 'IMAP',
          'USERDB_1_DRIVER' => 'prefetch',
          'USERNAME_CHARS' =>
'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@',
          'DOVECOT_MASTER' => '1',
          'RESTRICT_SETGID' => '',
          'AUTH_WORKER_MAX_COUNT' => '30',
          'AUTH_WORKER_PATH' => '/var/run/dovecot/auth-worker.25291',
          'PASSDB_2_ARGS' => '/etc/exim/checkp %d',
          'USERNAME_FORMAT' => '',
          'LOCAL_IP' => '128.177.27.100',
          'PASSDB_2_DRIVER' => 'checkpassword',
          'PASSDB_1_DRIVER' => 'pam',
          'REALMS' => '',
          'PROTO' => 'TCP',
          'ANONYMOUS_USERNAME' => 'anonymous',
          'RESTRICT_SETEXTRAGROUPS' => '',
          'TCPLOCALIP' => '128.177.27.100',
          'LOG_TO_MASTER' => '1',
          'MASTER_USER_SEPARATOR' => '',
          'RESTRICT_SETUID' => '',
          'REMOTE_IP' => '213.31.43.3',
          'RESTRICT_USER' => '',
          'DOVECOT_VERSION' => '1.0.rc15',
          'MECHANISMS' => 'plain',
          'RESTRICT_CHROOT' => '',
          'DEFAULT_REALM' => ''
        };

ARGS:
@ARGV = [
          '%d',
          '/usr/libexec/dovecot/checkpassword-reply'
        ];

Thanks,
Sawyer.