compatibility with Microsoft's
    AUTH LOGIN [base64 encoded user name ]
patch by Maxim Dounin
diff --git a/src/mail/ngx_mail.h b/src/mail/ngx_mail.h
index 4052efe..f813911 100644
--- a/src/mail/ngx_mail.h
+++ b/src/mail/ngx_mail.h
@@ -258,11 +258,12 @@
 #define NGX_SMTP_STARTTLS      13
 
 
-#define NGX_MAIL_AUTH_PLAIN     0
-#define NGX_MAIL_AUTH_LOGIN     1
-#define NGX_MAIL_AUTH_APOP      2
-#define NGX_MAIL_AUTH_CRAM_MD5  3
-#define NGX_MAIL_AUTH_NONE      4
+#define NGX_MAIL_AUTH_PLAIN             0
+#define NGX_MAIL_AUTH_LOGIN             1
+#define NGX_MAIL_AUTH_LOGIN_USERNAME    2
+#define NGX_MAIL_AUTH_APOP              3
+#define NGX_MAIL_AUTH_CRAM_MD5          4
+#define NGX_MAIL_AUTH_NONE              5
 
 
 #define NGX_MAIL_AUTH_PLAIN_ENABLED     0x0002
@@ -346,7 +347,7 @@
 ngx_int_t ngx_mail_auth_plain(ngx_mail_session_t *s, ngx_connection_t *c,
     ngx_uint_t n);
 ngx_int_t ngx_mail_auth_login_username(ngx_mail_session_t *s,
-    ngx_connection_t *c);
+    ngx_connection_t *c, ngx_uint_t n);
 ngx_int_t ngx_mail_auth_login_password(ngx_mail_session_t *s,
     ngx_connection_t *c);
 ngx_int_t ngx_mail_auth_cram_md5_salt(ngx_mail_session_t *s,
diff --git a/src/mail/ngx_mail_handler.c b/src/mail/ngx_mail_handler.c
index e86877f..0863d6d 100644
--- a/src/mail/ngx_mail_handler.c
+++ b/src/mail/ngx_mail_handler.c
@@ -356,21 +356,22 @@
 
 
 ngx_int_t
-ngx_mail_auth_login_username(ngx_mail_session_t *s, ngx_connection_t *c)
+ngx_mail_auth_login_username(ngx_mail_session_t *s, ngx_connection_t *c,
+    ngx_uint_t n)
 {
     ngx_str_t  *arg;
 
     arg = s->args.elts;
 
     ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0,
-                   "mail auth login username: \"%V\"", &arg[0]);
+                   "mail auth login username: \"%V\"", &arg[n]);
 
-    s->login.data = ngx_pnalloc(c->pool, ngx_base64_decoded_length(arg[0].len));
+    s->login.data = ngx_pnalloc(c->pool, ngx_base64_decoded_length(arg[n].len));
     if (s->login.data == NULL){
         return NGX_ERROR;
     }
 
-    if (ngx_decode_base64(&s->login, &arg[0]) != NGX_OK) {
+    if (ngx_decode_base64(&s->login, &arg[n]) != NGX_OK) {
         ngx_log_error(NGX_LOG_INFO, c->log, 0,
             "client sent invalid base64 encoding in AUTH LOGIN command");
         return NGX_MAIL_PARSE_INVALID_COMMAND;
diff --git a/src/mail/ngx_mail_imap_handler.c b/src/mail/ngx_mail_imap_handler.c
index 780c38f..a2e032e 100644
--- a/src/mail/ngx_mail_imap_handler.c
+++ b/src/mail/ngx_mail_imap_handler.c
@@ -205,7 +205,7 @@
             break;
 
         case ngx_imap_auth_login_username:
-            rc = ngx_mail_auth_login_username(s, c);
+            rc = ngx_mail_auth_login_username(s, c, 0);
 
             tag = 0;
             s->out.len = sizeof(imap_password) - 1;
@@ -370,6 +370,14 @@
 
         return NGX_OK;
 
+    case NGX_MAIL_AUTH_LOGIN_USERNAME:
+
+        s->out.len = sizeof(imap_password) - 1;
+        s->out.data = imap_password;
+        s->mail_state = ngx_imap_auth_login_password;
+
+        return ngx_mail_auth_login_username(s, c, 1);
+
     case NGX_MAIL_AUTH_PLAIN:
 
         s->out.len = sizeof(imap_plain_next) - 1;
diff --git a/src/mail/ngx_mail_parse.c b/src/mail/ngx_mail_parse.c
index a2d3f48..67f4d5e 100644
--- a/src/mail/ngx_mail_parse.c
+++ b/src/mail/ngx_mail_parse.c
@@ -848,6 +848,10 @@
                 return NGX_MAIL_AUTH_LOGIN;
             }
 
+            if (s->args.nelts == 2) {
+                return NGX_MAIL_AUTH_LOGIN_USERNAME;
+            }
+
             return NGX_MAIL_PARSE_INVALID_COMMAND;
         }
 
diff --git a/src/mail/ngx_mail_pop3_handler.c b/src/mail/ngx_mail_pop3_handler.c
index c763f04..aed6629 100644
--- a/src/mail/ngx_mail_pop3_handler.c
+++ b/src/mail/ngx_mail_pop3_handler.c
@@ -226,7 +226,7 @@
             break;
 
         case ngx_pop3_auth_login_username:
-            rc = ngx_mail_auth_login_username(s, c);
+            rc = ngx_mail_auth_login_username(s, c, 0);
 
             s->out.len = sizeof(pop3_password) - 1;
             s->out.data = pop3_password;
@@ -474,6 +474,14 @@
 
         return NGX_OK;
 
+    case NGX_MAIL_AUTH_LOGIN_USERNAME:
+
+        s->out.len = sizeof(pop3_password) - 1;
+        s->out.data = pop3_password;
+        s->mail_state = ngx_pop3_auth_login_password;
+
+        return ngx_mail_auth_login_username(s, c, 1);
+
     case NGX_MAIL_AUTH_PLAIN:
 
         s->out.len = sizeof(pop3_next) - 1;
diff --git a/src/mail/ngx_mail_smtp_handler.c b/src/mail/ngx_mail_smtp_handler.c
index a88a82c..a0ad37f 100644
--- a/src/mail/ngx_mail_smtp_handler.c
+++ b/src/mail/ngx_mail_smtp_handler.c
@@ -462,7 +462,7 @@
             break;
 
         case ngx_smtp_auth_login_username:
-            rc = ngx_mail_auth_login_username(s, c);
+            rc = ngx_mail_auth_login_username(s, c, 0);
 
             s->out.len = sizeof(smtp_password) - 1;
             s->out.data = smtp_password;
@@ -611,6 +611,14 @@
 
         return NGX_OK;
 
+    case NGX_MAIL_AUTH_LOGIN_USERNAME:
+
+        s->out.len = sizeof(smtp_password) - 1;
+        s->out.data = smtp_password;
+        s->mail_state = ngx_smtp_auth_login_password;
+
+        return ngx_mail_auth_login_username(s, c, 1);
+
     case NGX_MAIL_AUTH_PLAIN:
 
         s->out.len = sizeof(smtp_next) - 1;