IMAP proxy problems

[Attila Nagy]

Hello,

I'm trying to set up nginx (stable and devel, both without success) as 
an IMAP proxy to an Exchange server.

The config is:
daemon off;
error_log  /var/log/nginx-error.log debug;
events {
    worker_connections  1024;
}
mail {
    auth_http  127.0.0.1:9000/cgi-bin/auth;
    imap_capabilities  "IMAP4rev1"  "UIDPLUS";

    server {
        listen     143;
        protocol   imap;
        proxy      on;
    }
}

I give back on TCP/9000 the following:
HTTP/1.0 200 OK
Auth-Status: OK
Auth-Server: 127.0.0.1
Auth-Port: 1433
(this is just a test on a forwarded port)

What I get in the log:
2007/08/16 16:06:43 [info] 38634#0: *6 client  connected to
2007/08/16 16:06:48 [error] 38634#0: *6 upstream sent invalid response: 
"LOGIN BAD Protocol Error: "Unknown command found"." while reading 
response from upstream, client: , server: , login: "", upstream:

If I trace nginx, I see the following IO:
 38634 nginx    GIO   fd 8 read 103 bytes
       "* OK Microsoft Exchange Server 2003 IMAP4rev1 server version 
6.5.7638.\
        1 (MAILSRV) ready.\r
       "
 38634 nginx    RET   recvfrom 103/0x67
 38634 nginx    CALL  sendto(0x8,0x3f1140,0xb,0,0,0)
 38634 nginx    GIO   fd 8 wrote 11 bytes
       "LOGIN {6}\r
       "
 38634 nginx    RET   sendto 11/0xb
 38634 nginx    CALL  kevent(0x7,0x40c000,0,0x414000,0x200,0x7fdffffe3b0)
 38634 nginx    RET   kevent 2
 38634 nginx    CALL  gettimeofday(0x7fdffffe250,0)
 38634 nginx    RET   gettimeofday 0
 38634 nginx    CALL  recvfrom(0x8,0x47c000,0x2000,0,0,0)
 38634 nginx    GIO   fd 8 read 38 bytes
       "+ Ready for additional command text.\r
       "
 38634 nginx    RET   recvfrom 38/0x26
 38634 nginx    CALL  sendto(0x8,0x3f1170,0x6,0,0,0)
 38634 nginx    GIO   fd 8 wrote 6 bytes
       " {8}\r
       "
 38634 nginx    RET   sendto 6
 38634 nginx    CALL  kevent(0x7,0x40c000,0,0x414000,0x200,0x7fdffffe3b0)
 38634 nginx    RET   kevent 2
 38634 nginx    CALL  gettimeofday(0x7fdffffe250,0)
 38634 nginx    RET   gettimeofday 0
 38634 nginx    CALL  recvfrom(0x8,0x47c000,0x2000,0,0,0)
 38634 nginx    GIO   fd 8 read 52 bytes
       "LOGIN BAD Protocol Error: "Unknown command found".\r
       "

The OS is FreeBSD/sparc64, version 6-STABLE, nginx linked statically (if 
that counts).

Please keep me on cc, I'm not subscribed.

Thanks,