diff -cr /var/tmp/postfix-2.5.2/src/global/mail_proto.h ./src/global/mail_proto.h
*** /var/tmp/postfix-2.5.2/src/global/mail_proto.h	2007-12-12 15:28:28.000000000 -0500
--- ./src/global/mail_proto.h	2008-07-04 07:38:21.000000000 -0400
***************
*** 203,208 ****
--- 203,209 ----
  #define XCLIENT_PORT		"PORT"	/* client port */
  #define XCLIENT_PROTO		"PROTO"	/* client protocol */
  #define XCLIENT_HELO		"HELO"	/* client helo */
+ #define XCLIENT_LOGIN		"LOGIN"	/* client login */
  
  #define XCLIENT_UNAVAILABLE	"[UNAVAILABLE]"	/* permanently unavailable */
  #define XCLIENT_TEMPORARY	"[TEMPUNAVAIL]"	/* temporarily unavailable */
diff -cr /var/tmp/postfix-2.5.2/src/smtpd/smtpd.c ./src/smtpd/smtpd.c
*** /var/tmp/postfix-2.5.2/src/smtpd/smtpd.c	2008-05-08 20:12:00.000000000 -0400
--- ./src/smtpd/smtpd.c	2008-07-09 08:33:35.000000000 -0400
***************
*** 1557,1563 ****
  	    ENQUEUE_FIX_REPLY(state, reply_buf, XCLIENT_CMD
  			      " " XCLIENT_NAME " " XCLIENT_ADDR
  			      " " XCLIENT_PROTO " " XCLIENT_HELO
! 			      " " XCLIENT_REVERSE_NAME " " XCLIENT_PORT);
      if ((discard_mask & EHLO_MASK_XFORWARD) == 0)
  	if (xforward_allowed)
  	    ENQUEUE_FIX_REPLY(state, reply_buf, XFORWARD_CMD
--- 1557,1564 ----
  	    ENQUEUE_FIX_REPLY(state, reply_buf, XCLIENT_CMD
  			      " " XCLIENT_NAME " " XCLIENT_ADDR
  			      " " XCLIENT_PROTO " " XCLIENT_HELO
! 			      " " XCLIENT_REVERSE_NAME " " XCLIENT_PORT
!                   " " XCLIENT_LOGIN);
      if ((discard_mask & EHLO_MASK_XFORWARD) == 0)
  	if (xforward_allowed)
  	    ENQUEUE_FIX_REPLY(state, reply_buf, XFORWARD_CMD
***************
*** 3195,3200 ****
--- 3196,3202 ----
      };
      int     got_helo = 0;
      int     got_proto = 0;
+     int     got_login =0;
  
      /*
       * Sanity checks.
***************
*** 3386,3391 ****
--- 3388,3406 ----
  	    UPDATE_STR(state->protocol, uppercase(attr_value));
  	    got_proto = 1;
  	}
+     
+     /*
+ 	 * LOGIN=substitute SMTP client username has been authenticated.
+ 	 */
+ 	else if (STREQ(attr_name, XCLIENT_LOGIN)) {
+ 	    if (STREQ(attr_value, XCLIENT_UNAVAILABLE)) {
+                 attr_value = CLIENT_LOGIN_UNKNOWN;
+ 	    }
+ 	    UPDATE_STR(state->sasl_username, attr_value);
+             printable(state->sasl_username, '?');
+             UPDATE_STR(state->sasl_method, "xclient");
+             got_login = 1;
+ 	}
  
  	/*
  	 * Unknown attribute name. Complain.
***************
*** 3436,3442 ****
      }
  #ifdef USE_SASL_AUTH
      if (var_smtpd_sasl_enable)
! 	smtpd_sasl_auth_reset(state);
  #endif
      chat_reset(state, 0);
      mail_reset(state);
--- 3451,3458 ----
      }
  #ifdef USE_SASL_AUTH
      if (var_smtpd_sasl_enable)
!          if (got_proto == 0)
!               smtpd_sasl_auth_reset(state);
  #endif
      chat_reset(state, 0);
      mail_reset(state);
diff -cr /var/tmp/postfix-2.5.2/src/smtpd/smtpd.h ./src/smtpd/smtpd.h
*** /var/tmp/postfix-2.5.2/src/smtpd/smtpd.h	2008-04-29 20:49:01.000000000 -0400
--- ./src/smtpd/smtpd.h	2008-07-07 13:35:06.000000000 -0400
***************
*** 242,247 ****
--- 242,248 ----
  #define CLIENT_PROTO_UNKNOWN	CLIENT_ATTR_UNKNOWN
  #define CLIENT_IDENT_UNKNOWN	0
  #define CLIENT_DOMAIN_UNKNOWN	0
+ #define CLIENT_LOGIN_UNKNOWN	0
  
  #define IS_AVAIL_CLIENT_ATTR(v)	((v) && strcmp((v), CLIENT_ATTR_UNKNOWN))