--- a/src/mail/ngx_mail_proxy_module.c
+++ b/src/mail/ngx_mail_proxy_module.c
@@ -104,7 +104,7 @@ ngx_module_t  ngx_mail_proxy_module = {
 };
 
 
-static u_char  smtp_ok[] = "235 2.0.0 OK" CRLF;
+static u_char  smtp_ok[] = "250 2.0.0 OK" CRLF;
 
 
 void
@@ -201,7 +201,7 @@ ngx_mail_proxy_block_read(ngx_event_t *r
 
     ngx_log_debug0(NGX_LOG_DEBUG_MAIL, rev->log, 0, "mail proxy block read");
 
-    if (ngx_handle_read_event(rev, 0) == NGX_ERROR) {
+    if (ngx_handle_read_event(rev, 0) != NGX_OK) {
         c = rev->data;
         s = c->data;
 
@@ -465,6 +465,7 @@ ngx_mail_proxy_smtp_handler(ngx_event_t 
     u_char                    *p;
     ngx_int_t                  rc;
     ngx_str_t                  line;
+    ngx_buf_t                 *b;
     ngx_connection_t          *c;
     ngx_mail_session_t        *s;
     ngx_mail_proxy_conf_t     *pcf;
@@ -520,9 +521,15 @@ ngx_mail_proxy_smtp_handler(ngx_event_t 
         p = ngx_cpymem(p, cscf->server_name.data, cscf->server_name.len);
         *p++ = CR; *p = LF;
 
-        s->mail_state = pcf->xclient ? ngx_smtp_helo_xclient :
-                        s->auth_method == NGX_MAIL_AUTH_NONE ?
-                        ngx_smtp_helo_from : ngx_smtp_helo;
+        if (pcf->xclient) {
+            s->mail_state = ngx_smtp_helo_xclient;
+
+        } else if (s->auth_method == NGX_MAIL_AUTH_NONE) {
+            s->mail_state = ngx_smtp_helo_from;
+
+        } else {
+            s->mail_state = ngx_smtp_helo;
+        }
 
         break;
 
@@ -544,16 +551,15 @@ ngx_mail_proxy_smtp_handler(ngx_event_t 
         }
 
         line.len = ngx_sprintf(line.data,
-                       "XCLIENT PROTO=%sSMTP%s%V ADDR=%V%s%V "
-                       "NAME=%V" CRLF,
-                       (s->esmtp ? "E" : ""), 
+                       "XCLIENT PROTO=%sSMTP%s%V ADDR=%V%s%V NAME=%V" CRLF,
+                       (s->esmtp ? "E" : ""),
                        (s->smtp_helo.len ? " HELO=" : ""), &s->smtp_helo,
                        &s->connection->addr_text,
                        (s->login.len ? " LOGIN=" : ""), &s->login, &s->host)
                    - line.data;
 
-        s->mail_state = s->auth_method == NGX_MAIL_AUTH_NONE ?
-                        ngx_smtp_xclient_from : ngx_smtp_xclient;
+        s->mail_state = (s->auth_method == NGX_MAIL_AUTH_NONE) ?
+                            ngx_smtp_xclient_from : ngx_smtp_xclient;
 
         break;
 
@@ -602,15 +608,16 @@ ngx_mail_proxy_smtp_handler(ngx_event_t 
     case ngx_smtp_xclient:
     case ngx_smtp_to:
 
-        if (s->auth_method != NGX_MAIL_AUTH_NONE) {
-            ngx_memcpy(s->proxy->buffer->start, smtp_ok,
-                       sizeof(smtp_ok) - 1);
-            s->proxy->buffer->last = s->proxy->buffer->start
-                + sizeof(smtp_ok) - 1;
-            s->proxy->buffer->pos = s->proxy->buffer->start;
+        b = s->proxy->buffer;
+
+        if (s->auth_method == NGX_MAIL_AUTH_NONE) {
+            b->pos = b->start;
+
+        } else {
+            ngx_memcpy(b->start, smtp_ok, sizeof(smtp_ok) - 1);
+            b->last = b->start + sizeof(smtp_ok) - 1;
         }
 
-
         s->connection->read->handler = ngx_mail_proxy_handler;
         s->connection->write->handler = ngx_mail_proxy_handler;
         rev->handler = ngx_mail_proxy_handler;
@@ -662,7 +669,7 @@ ngx_mail_proxy_dummy_handler(ngx_event_t
 
     ngx_log_debug0(NGX_LOG_DEBUG_MAIL, wev->log, 0, "mail proxy dummy handler");
 
-    if (ngx_handle_write_event(wev, 0) == NGX_ERROR) {
+    if (ngx_handle_write_event(wev, 0) != NGX_OK) {
         c = wev->data;
         s = c->data;
 
@@ -753,20 +760,17 @@ ngx_mail_proxy_read_response(ngx_mail_se
     default: /* NGX_MAIL_SMTP_PROTOCOL */
         switch (state) {
 
-        case ngx_smtp_to:
-            return NGX_OK;
-
-        case ngx_smtp_helo:
-        case ngx_smtp_helo_from:
-        case ngx_smtp_helo_xclient:
-        case ngx_smtp_from:
-            if (p[0] == '2' && p[1] == '5' && p[2] == '0') {
+        case ngx_smtp_start:
+            if (p[0] == '2' && p[1] == '2' && p[2] == '0') {
                 return NGX_OK;
             }
             break;
 
-        case ngx_smtp_start:
-            if (p[0] == '2' && p[1] == '2' && p[2] == '0') {
+        case ngx_smtp_helo:
+        case ngx_smtp_helo_xclient:
+        case ngx_smtp_helo_from:
+        case ngx_smtp_from:
+            if (p[0] == '2' && p[1] == '5' && p[2] == '0') {
                 return NGX_OK;
             }
             break;
@@ -777,6 +781,9 @@ ngx_mail_proxy_read_response(ngx_mail_se
                 return NGX_OK;
             }
             break;
+
+        case ngx_smtp_to:
+            return NGX_OK;
         }
 
         break;
@@ -945,22 +952,22 @@ ngx_mail_proxy_handler(ngx_event_t *ev)
         return;
     }
 
-    if (ngx_handle_write_event(dst->write, 0) == NGX_ERROR) {
+    if (ngx_handle_write_event(dst->write, 0) != NGX_OK) {
         ngx_mail_proxy_close_session(s);
         return;
     }
 
-    if (ngx_handle_read_event(dst->read, 0) == NGX_ERROR) {
+    if (ngx_handle_read_event(dst->read, 0) != NGX_OK) {
         ngx_mail_proxy_close_session(s);
         return;
     }
 
-    if (ngx_handle_write_event(src->write, 0) == NGX_ERROR) {
+    if (ngx_handle_write_event(src->write, 0) != NGX_OK) {
         ngx_mail_proxy_close_session(s);
         return;
     }
 
-    if (ngx_handle_read_event(src->read, 0) == NGX_ERROR) {
+    if (ngx_handle_read_event(src->read, 0) != NGX_OK) {
         ngx_mail_proxy_close_session(s);
         return;
     }