Not passing escaped @ in username

[hanoidesign]

Hello everyone,

I am running Roundcube    0.7.1.

When login, it passes name\@domain.com as the username, and pam generates error. How can I config that @ is not escaped?

I am running dovecot imap pam authentication with FLAG = -r.  It works well with Outlook etc.

Here are logs from Roundcube:

Error:

[20-Jun-2012 09:42:21 +0000]: IMAP Error: Login failed for noreply\@domain.com from (X-Forwarded-For: ). AUTHENTICATE PLAIN: Authentication failed. in /var/www_old/html/roundcube/program/include/rcube_imap.php on line 205 (POST /roundcube/?_task=login&_action=login)

IMAP:

[20-Jun-2012 11:43:16 +0000]: [3C09] S: * OK Dovecot ready.
[20-Jun-2012 11:43:16 +0000]: [3C09] C: A0001 CAPABILITY
[20-Jun-2012 11:43:16 +0000]: [3C09] S: * CAPABILITY IMAP4rev1 SASL-IR SORT THREAD=REFERENCES MULTIAPPEND UNSELECT LITERAL+ IDLE CHILDREN NAMESPACE LOGIN-REFERRALS STARTTLS AUTH=PLAIN AUTH=LOGIN
[20-Jun-2012 11:43:16 +0000]: [3C09] S: A0001 OK Capability completed.
[20-Jun-2012 11:43:16 +0000]: [3C09] C: A0002 LOGIN "noreply\\@domain.com" pw
[20-Jun-2012 11:43:19 +0000]: [3C09] S: A0002 NO Authentication failed.
[20-Jun-2012 11:43:19 +0000]: [3C09] C: A0003 LOGOUT
[20-Jun-2012 11:43:19 +0000]: [3C09] S: * BYE Logging out
[20-Jun-2012 11:43:19 +0000]: [3C09] S: A0003 OK Logout completed.

Message:

Jun 20 11:43:18 sbox dovecot: auth(default): pam(noreply\@domain.com,::ffff:127.0.0.1): pam_authenticate() failed: User not known to the underlying authentication module
Jun 20 11:43:19 sbox dovecot: imap-login: Aborted login: user=<noreply\@domain.com>, method=PLAIN, rip=::ffff:127.0.0.1, lip=::ffff:127.0.0.1, secured

Thank you.