copy from src/imap/ngx_imap_proxy_module.c
copy to src/mail/ngx_mail_proxy_module.c
--- a/src/imap/ngx_imap_proxy_module.c
+++ b/src/mail/ngx_mail_proxy_module.c
@@ -8,80 +8,89 @@
 #include <ngx_core.h>
 #include <ngx_event.h>
 #include <ngx_event_connect.h>
-#include <ngx_imap.h>
+#include <ngx_mail.h>
 
 
 typedef struct {
     ngx_flag_t  enable;
     ngx_flag_t  pass_error_message;
+    ngx_flag_t  xclient;
     size_t      buffer_size;
     ngx_msec_t  timeout;
-} ngx_imap_proxy_conf_t;
+} ngx_mail_proxy_conf_t;
 
 
-static void ngx_imap_proxy_block_read(ngx_event_t *rev);
-static void ngx_imap_proxy_imap_handler(ngx_event_t *rev);
-static void ngx_imap_proxy_pop3_handler(ngx_event_t *rev);
-static void ngx_imap_proxy_dummy_handler(ngx_event_t *ev);
-static ngx_int_t ngx_imap_proxy_read_response(ngx_imap_session_t *s,
+static void ngx_mail_proxy_block_read(ngx_event_t *rev);
+static void ngx_mail_proxy_pop3_handler(ngx_event_t *rev);
+static void ngx_mail_proxy_imap_handler(ngx_event_t *rev);
+static void ngx_mail_proxy_smtp_handler(ngx_event_t *rev);
+static void ngx_mail_proxy_dummy_handler(ngx_event_t *ev);
+static ngx_int_t ngx_mail_proxy_read_response(ngx_mail_session_t *s,
     ngx_uint_t state);
-static void ngx_imap_proxy_handler(ngx_event_t *ev);
-static void ngx_imap_proxy_upstream_error(ngx_imap_session_t *s);
-static void ngx_imap_proxy_internal_server_error(ngx_imap_session_t *s);
-static void ngx_imap_proxy_close_session(ngx_imap_session_t *s);
-static void *ngx_imap_proxy_create_conf(ngx_conf_t *cf);
-static char *ngx_imap_proxy_merge_conf(ngx_conf_t *cf, void *parent,
+static void ngx_mail_proxy_handler(ngx_event_t *ev);
+static void ngx_mail_proxy_upstream_error(ngx_mail_session_t *s);
+static void ngx_mail_proxy_internal_server_error(ngx_mail_session_t *s);
+static void ngx_mail_proxy_close_session(ngx_mail_session_t *s);
+static void *ngx_mail_proxy_create_conf(ngx_conf_t *cf);
+static char *ngx_mail_proxy_merge_conf(ngx_conf_t *cf, void *parent,
     void *child);
 
 
-static ngx_command_t  ngx_imap_proxy_commands[] = {
+static ngx_command_t  ngx_mail_proxy_commands[] = {
 
     { ngx_string("proxy"),
-      NGX_IMAP_MAIN_CONF|NGX_IMAP_SRV_CONF|NGX_CONF_FLAG,
+      NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_FLAG,
       ngx_conf_set_flag_slot,
-      NGX_IMAP_SRV_CONF_OFFSET,
-      offsetof(ngx_imap_proxy_conf_t, enable),
+      NGX_MAIL_SRV_CONF_OFFSET,
+      offsetof(ngx_mail_proxy_conf_t, enable),
       NULL },
 
     { ngx_string("proxy_buffer"),
-      NGX_IMAP_MAIN_CONF|NGX_IMAP_SRV_CONF|NGX_CONF_TAKE1,
+      NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1,
       ngx_conf_set_size_slot,
-      NGX_IMAP_SRV_CONF_OFFSET,
-      offsetof(ngx_imap_proxy_conf_t, buffer_size),
+      NGX_MAIL_SRV_CONF_OFFSET,
+      offsetof(ngx_mail_proxy_conf_t, buffer_size),
       NULL },
 
     { ngx_string("proxy_timeout"),
-      NGX_IMAP_MAIN_CONF|NGX_IMAP_SRV_CONF|NGX_CONF_TAKE1,
+      NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1,
       ngx_conf_set_msec_slot,
-      NGX_IMAP_SRV_CONF_OFFSET,
-      offsetof(ngx_imap_proxy_conf_t, timeout),
+      NGX_MAIL_SRV_CONF_OFFSET,
+      offsetof(ngx_mail_proxy_conf_t, timeout),
       NULL },
 
     { ngx_string("proxy_pass_error_message"),
-      NGX_IMAP_MAIN_CONF|NGX_IMAP_SRV_CONF|NGX_CONF_TAKE1,
+      NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1,
       ngx_conf_set_flag_slot,
-      NGX_IMAP_SRV_CONF_OFFSET,
-      offsetof(ngx_imap_proxy_conf_t, pass_error_message),
+      NGX_MAIL_SRV_CONF_OFFSET,
+      offsetof(ngx_mail_proxy_conf_t, pass_error_message),
+      NULL },
+
+    { ngx_string("xclient"),
+      NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_FLAG,
+      ngx_conf_set_flag_slot,
+      NGX_MAIL_SRV_CONF_OFFSET,
+      offsetof(ngx_mail_proxy_conf_t, xclient),
       NULL },
 
       ngx_null_command
 };
 
 
-static ngx_imap_module_t  ngx_imap_proxy_module_ctx = {
+static ngx_mail_module_t  ngx_mail_proxy_module_ctx = {
     NULL,                                  /* create main configuration */
     NULL,                                  /* init main configuration */
 
-    ngx_imap_proxy_create_conf,            /* create server configuration */
-    ngx_imap_proxy_merge_conf              /* merge server configuration */
+    ngx_mail_proxy_create_conf,            /* create server configuration */
+    ngx_mail_proxy_merge_conf              /* merge server configuration */
 };
 
 
-ngx_module_t  ngx_imap_proxy_module = {
+ngx_module_t  ngx_mail_proxy_module = {
     NGX_MODULE_V1,
-    &ngx_imap_proxy_module_ctx,            /* module context */
-    ngx_imap_proxy_commands,               /* module directives */
-    NGX_IMAP_MODULE,                       /* module type */
+    &ngx_mail_proxy_module_ctx,            /* module context */
+    ngx_mail_proxy_commands,               /* module directives */
+    NGX_MAIL_MODULE,                       /* module type */
     NULL,                                  /* init master */
     NULL,                                  /* init module */
     NULL,                                  /* init process */
@@ -93,17 +102,21 @@ ngx_module_t  ngx_imap_proxy_module = {
 };
 
 
+static u_char  smtp_ok[] = "235 2.0.0 OK" CRLF;
+
+
 void
-ngx_imap_proxy_init(ngx_imap_session_t *s, ngx_peer_addr_t *peer)
+ngx_mail_proxy_init(ngx_mail_session_t *s, ngx_peer_addr_t *peer)
 {
     int                        keepalive;
     ngx_int_t                  rc;
-    ngx_imap_proxy_ctx_t      *p;
-    ngx_imap_core_srv_conf_t  *cscf;
+    ngx_mail_proxy_ctx_t      *p;
+    ngx_mail_proxy_conf_t     *pcf;
+    ngx_mail_core_srv_conf_t  *cscf;
 
     s->connection->log->action = "connecting to upstream";
 
-    cscf = ngx_imap_get_module_srv_conf(s, ngx_imap_core_module);
+    cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module);
 
     if (cscf->so_keepalive) {
         keepalive = 1;
@@ -117,9 +130,9 @@ ngx_imap_proxy_init(ngx_imap_session_t *
         }
     }
 
-    p = ngx_pcalloc(s->connection->pool, sizeof(ngx_imap_proxy_ctx_t));
+    p = ngx_pcalloc(s->connection->pool, sizeof(ngx_mail_proxy_ctx_t));
     if (p == NULL) {
-        ngx_imap_session_internal_server_error(s);
+        ngx_mail_session_internal_server_error(s);
         return;
     }
 
@@ -135,7 +148,7 @@ ngx_imap_proxy_init(ngx_imap_session_t *
     rc = ngx_event_connect_peer(&p->upstream);
 
     if (rc == NGX_ERROR || rc == NGX_BUSY || rc == NGX_DECLINED) {
-        ngx_imap_proxy_internal_server_error(s);
+        ngx_mail_proxy_internal_server_error(s);
         return;
     }
 
@@ -144,49 +157,67 @@ ngx_imap_proxy_init(ngx_imap_session_t *
     p->upstream.connection->data = s;
     p->upstream.connection->pool = s->connection->pool;
 
-    s->connection->read->handler = ngx_imap_proxy_block_read;
-    p->upstream.connection->write->handler = ngx_imap_proxy_dummy_handler;
+    s->connection->read->handler = ngx_mail_proxy_block_read;
+    p->upstream.connection->write->handler = ngx_mail_proxy_dummy_handler;
+
+    pcf = ngx_mail_get_module_srv_conf(s, ngx_mail_proxy_module);
+
+    s->proxy->buffer = ngx_create_temp_buf(s->connection->pool,
+                                           pcf->buffer_size);
+    if (s->proxy->buffer == NULL) {
+        ngx_mail_proxy_internal_server_error(s);
+        return;
+    }
+
+    switch (s->protocol) {
 
-    if (s->protocol == NGX_IMAP_POP3_PROTOCOL) {
-        p->upstream.connection->read->handler = ngx_imap_proxy_pop3_handler;
-        s->imap_state = ngx_pop3_start;
+    case NGX_MAIL_POP3_PROTOCOL:
+        p->upstream.connection->read->handler = ngx_mail_proxy_pop3_handler;
+        s->mail_state = ngx_pop3_start;
+        break;
 
-    } else {
-        p->upstream.connection->read->handler = ngx_imap_proxy_imap_handler;
-        s->imap_state = ngx_imap_start;
+    case NGX_MAIL_IMAP_PROTOCOL:
+        p->upstream.connection->read->handler = ngx_mail_proxy_imap_handler;
+        s->mail_state = ngx_imap_start;
+        break;
+
+    default: /* NGX_MAIL_SMTP_PROTOCOL */
+        p->upstream.connection->read->handler = ngx_mail_proxy_smtp_handler;
+        s->mail_state = ngx_smtp_start;
+        break;
     }
 }
 
 
 static void
-ngx_imap_proxy_block_read(ngx_event_t *rev)
+ngx_mail_proxy_block_read(ngx_event_t *rev)
 {
     ngx_connection_t    *c;
-    ngx_imap_session_t  *s;
+    ngx_mail_session_t  *s;
 
-    ngx_log_debug0(NGX_LOG_DEBUG_IMAP, rev->log, 0, "imap proxy block read");
+    ngx_log_debug0(NGX_LOG_DEBUG_MAIL, rev->log, 0, "mail proxy block read");
 
     if (ngx_handle_read_event(rev, 0) == NGX_ERROR) {
         c = rev->data;
         s = c->data;
 
-        ngx_imap_proxy_close_session(s);
+        ngx_mail_proxy_close_session(s);
     }
 }
 
 
 static void
-ngx_imap_proxy_imap_handler(ngx_event_t *rev)
+ngx_mail_proxy_pop3_handler(ngx_event_t *rev)
 {
     u_char                 *p;
     ngx_int_t               rc;
     ngx_str_t               line;
     ngx_connection_t       *c;
-    ngx_imap_session_t     *s;
-    ngx_imap_proxy_conf_t  *pcf;
+    ngx_mail_session_t     *s;
+    ngx_mail_proxy_conf_t  *pcf;
 
-    ngx_log_debug0(NGX_LOG_DEBUG_IMAP, rev->log, 0,
-                   "imap proxy imap auth handler");
+    ngx_log_debug0(NGX_LOG_DEBUG_MAIL, rev->log, 0,
+                   "mail proxy pop3 auth handler");
 
     c = rev->data;
     s = c->data;
@@ -195,106 +226,75 @@ ngx_imap_proxy_imap_handler(ngx_event_t 
         ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT,
                       "upstream timed out");
         c->timedout = 1;
-        ngx_imap_proxy_internal_server_error(s);
+        ngx_mail_proxy_internal_server_error(s);
         return;
     }
 
-    if (s->proxy->buffer == NULL) {
-        pcf = ngx_imap_get_module_srv_conf(s, ngx_imap_proxy_module);
-
-        s->proxy->buffer = ngx_create_temp_buf(c->pool, pcf->buffer_size);
-        if (s->proxy->buffer == NULL) {
-            ngx_imap_proxy_internal_server_error(s);
-            return;
-        }
-    }
-
-    rc = ngx_imap_proxy_read_response(s, s->imap_state);
+    rc = ngx_mail_proxy_read_response(s, 0);
 
     if (rc == NGX_AGAIN) {
         return;
     }
 
     if (rc == NGX_ERROR) {
-        ngx_imap_proxy_upstream_error(s);
+        ngx_mail_proxy_upstream_error(s);
         return;
     }
 
-    switch (s->imap_state) {
-
-    case ngx_imap_start:
-        ngx_log_debug0(NGX_LOG_DEBUG_IMAP, rev->log, 0,
-                       "imap proxy send login");
-
-        s->connection->log->action = "sending LOGIN command to upstream";
+    switch (s->mail_state) {
 
-        line.len = s->tag.len + sizeof("LOGIN ") - 1
-                   + 1 + NGX_SIZE_T_LEN + 1 + 2;
-        line.data = ngx_palloc(c->pool, line.len);
-        if (line.data == NULL) {
-            ngx_imap_proxy_internal_server_error(s);
-            return;
-        }
-
-        line.len = ngx_sprintf(line.data, "%VLOGIN {%uz}" CRLF,
-                               &s->tag, s->login.len)
-                   - line.data;
-
-        s->imap_state = ngx_imap_login;
-        break;
-
-    case ngx_imap_login:
-        ngx_log_debug0(NGX_LOG_DEBUG_IMAP, rev->log, 0, "imap proxy send user");
+    case ngx_pop3_start:
+        ngx_log_debug0(NGX_LOG_DEBUG_MAIL, rev->log, 0, "mail proxy send user");
 
         s->connection->log->action = "sending user name to upstream";
 
-        line.len = s->login.len + 1 + 1 + NGX_SIZE_T_LEN + 1 + 2;
+        line.len = sizeof("USER ")  - 1 + s->login.len + 2;
         line.data = ngx_palloc(c->pool, line.len);
         if (line.data == NULL) {
-            ngx_imap_proxy_internal_server_error(s);
+            ngx_mail_proxy_internal_server_error(s);
             return;
         }
 
-        line.len = ngx_sprintf(line.data, "%V {%uz}" CRLF,
-                               &s->login, s->passwd.len)
-                   - line.data;
+        p = ngx_cpymem(line.data, "USER ", sizeof("USER ") - 1);
+        p = ngx_cpymem(p, s->login.data, s->login.len);
+        *p++ = CR; *p = LF;
 
-        s->imap_state = ngx_imap_user;
+        s->mail_state = ngx_pop3_user;
         break;
 
-    case ngx_imap_user:
-        ngx_log_debug0(NGX_LOG_DEBUG_IMAP, rev->log, 0,
-                       "imap proxy send passwd");
+    case ngx_pop3_user:
+        ngx_log_debug0(NGX_LOG_DEBUG_MAIL, rev->log, 0, "mail proxy send pass");
 
         s->connection->log->action = "sending password to upstream";
 
-        line.len = s->passwd.len + 2;
+        line.len = sizeof("PASS ")  - 1 + s->passwd.len + 2;
         line.data = ngx_palloc(c->pool, line.len);
         if (line.data == NULL) {
-            ngx_imap_proxy_internal_server_error(s);
+            ngx_mail_proxy_internal_server_error(s);
             return;
         }
 
-        p = ngx_cpymem(line.data, s->passwd.data, s->passwd.len);
+        p = ngx_cpymem(line.data, "PASS ", sizeof("PASS ") - 1);
+        p = ngx_cpymem(p, s->passwd.data, s->passwd.len);
         *p++ = CR; *p = LF;
 
-        s->imap_state = ngx_imap_passwd;
+        s->mail_state = ngx_pop3_passwd;
         break;
 
-    case ngx_imap_passwd:
-        s->connection->read->handler = ngx_imap_proxy_handler;
-        s->connection->write->handler = ngx_imap_proxy_handler;
-        rev->handler = ngx_imap_proxy_handler;
-        c->write->handler = ngx_imap_proxy_handler;
+    case ngx_pop3_passwd:
+        s->connection->read->handler = ngx_mail_proxy_handler;
+        s->connection->write->handler = ngx_mail_proxy_handler;
+        rev->handler = ngx_mail_proxy_handler;
+        c->write->handler = ngx_mail_proxy_handler;
 
-        pcf = ngx_imap_get_module_srv_conf(s, ngx_imap_proxy_module);
+        pcf = ngx_mail_get_module_srv_conf(s, ngx_mail_proxy_module);
         ngx_add_timer(s->connection->read, pcf->timeout);
         ngx_del_timer(c->read);
 
         c->log->action = NULL;
         ngx_log_error(NGX_LOG_INFO, c->log, 0, "client logged in");
 
-        ngx_imap_proxy_handler(s->connection->write);
+        ngx_mail_proxy_handler(s->connection->write);
 
         return;
 
@@ -311,7 +311,7 @@ ngx_imap_proxy_imap_handler(ngx_event_t 
          * we treat the incomplete sending as NGX_ERROR
          * because it is very strange here
          */
-        ngx_imap_proxy_internal_server_error(s);
+        ngx_mail_proxy_internal_server_error(s);
         return;
     }
 
@@ -321,17 +321,17 @@ ngx_imap_proxy_imap_handler(ngx_event_t 
 
 
 static void
-ngx_imap_proxy_pop3_handler(ngx_event_t *rev)
+ngx_mail_proxy_imap_handler(ngx_event_t *rev)
 {
     u_char                 *p;
     ngx_int_t               rc;
     ngx_str_t               line;
     ngx_connection_t       *c;
-    ngx_imap_session_t     *s;
-    ngx_imap_proxy_conf_t  *pcf;
+    ngx_mail_session_t     *s;
+    ngx_mail_proxy_conf_t  *pcf;
 
-    ngx_log_debug0(NGX_LOG_DEBUG_IMAP, rev->log, 0,
-                   "imap proxy pop3 auth handler");
+    ngx_log_debug0(NGX_LOG_DEBUG_MAIL, rev->log, 0,
+                   "mail proxy imap auth handler");
 
     c = rev->data;
     s = c->data;
@@ -340,85 +340,96 @@ ngx_imap_proxy_pop3_handler(ngx_event_t 
         ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT,
                       "upstream timed out");
         c->timedout = 1;
-        ngx_imap_proxy_internal_server_error(s);
+        ngx_mail_proxy_internal_server_error(s);
         return;
     }
 
-    if (s->proxy->buffer == NULL) {
-        pcf = ngx_imap_get_module_srv_conf(s, ngx_imap_proxy_module);
-
-        s->proxy->buffer = ngx_create_temp_buf(c->pool, pcf->buffer_size);
-        if (s->proxy->buffer == NULL) {
-            ngx_imap_proxy_internal_server_error(s);
-            return;
-        }
-    }
-
-    rc = ngx_imap_proxy_read_response(s, 0);
+    rc = ngx_mail_proxy_read_response(s, s->mail_state);
 
     if (rc == NGX_AGAIN) {
         return;
     }
 
     if (rc == NGX_ERROR) {
-        ngx_imap_proxy_upstream_error(s);
+        ngx_mail_proxy_upstream_error(s);
         return;
     }
 
-    switch (s->imap_state) {
+    switch (s->mail_state) {
 
-    case ngx_pop3_start:
-        ngx_log_debug0(NGX_LOG_DEBUG_IMAP, rev->log, 0, "imap proxy send user");
+    case ngx_imap_start:
+        ngx_log_debug0(NGX_LOG_DEBUG_MAIL, rev->log, 0,
+                       "mail proxy send login");
 
-        s->connection->log->action = "sending user name to upstream";
+        s->connection->log->action = "sending LOGIN command to upstream";
 
-        line.len = sizeof("USER ")  - 1 + s->login.len + 2;
+        line.len = s->tag.len + sizeof("LOGIN ") - 1
+                   + 1 + NGX_SIZE_T_LEN + 1 + 2;
         line.data = ngx_palloc(c->pool, line.len);
         if (line.data == NULL) {
-            ngx_imap_proxy_internal_server_error(s);
+            ngx_mail_proxy_internal_server_error(s);
             return;
         }
 
-        p = ngx_cpymem(line.data, "USER ", sizeof("USER ") - 1);
-        p = ngx_cpymem(p, s->login.data, s->login.len);
-        *p++ = CR; *p = LF;
+        line.len = ngx_sprintf(line.data, "%VLOGIN {%uz}" CRLF,
+                               &s->tag, s->login.len)
+                   - line.data;
 
-        s->imap_state = ngx_pop3_user;
+        s->mail_state = ngx_imap_login;
         break;
 
-    case ngx_pop3_user:
-        ngx_log_debug0(NGX_LOG_DEBUG_IMAP, rev->log, 0, "imap proxy send pass");
+    case ngx_imap_login:
+        ngx_log_debug0(NGX_LOG_DEBUG_MAIL, rev->log, 0, "mail proxy send user");
+
+        s->connection->log->action = "sending user name to upstream";
+
+        line.len = s->login.len + 1 + 1 + NGX_SIZE_T_LEN + 1 + 2;
+        line.data = ngx_palloc(c->pool, line.len);
+        if (line.data == NULL) {
+            ngx_mail_proxy_internal_server_error(s);
+            return;
+        }
+
+        line.len = ngx_sprintf(line.data, "%V {%uz}" CRLF,
+                               &s->login, s->passwd.len)
+                   - line.data;
+
+        s->mail_state = ngx_imap_user;
+        break;
+
+    case ngx_imap_user:
+        ngx_log_debug0(NGX_LOG_DEBUG_MAIL, rev->log, 0,
+                       "mail proxy send passwd");
 
         s->connection->log->action = "sending password to upstream";
 
-        line.len = sizeof("PASS ")  - 1 + s->passwd.len + 2;
+        line.len = s->passwd.len + 2;
         line.data = ngx_palloc(c->pool, line.len);
         if (line.data == NULL) {
-            ngx_imap_proxy_internal_server_error(s);
+            ngx_mail_proxy_internal_server_error(s);
             return;
         }
 
-        p = ngx_cpymem(line.data, "PASS ", sizeof("PASS ") - 1);
-        p = ngx_cpymem(p, s->passwd.data, s->passwd.len);
+        p = ngx_cpymem(line.data, s->passwd.data, s->passwd.len);
         *p++ = CR; *p = LF;
 
-        s->imap_state = ngx_pop3_passwd;
+        s->mail_state = ngx_imap_passwd;
         break;
 
-    case ngx_pop3_passwd:
-        s->connection->read->handler = ngx_imap_proxy_handler;
-        s->connection->write->handler = ngx_imap_proxy_handler;
-        rev->handler = ngx_imap_proxy_handler;
-        c->write->handler = ngx_imap_proxy_handler;
+    case ngx_imap_passwd:
+        s->connection->read->handler = ngx_mail_proxy_handler;
+        s->connection->write->handler = ngx_mail_proxy_handler;
+        rev->handler = ngx_mail_proxy_handler;
+        c->write->handler = ngx_mail_proxy_handler;
 
-        pcf = ngx_imap_get_module_srv_conf(s, ngx_imap_proxy_module);
+        pcf = ngx_mail_get_module_srv_conf(s, ngx_mail_proxy_module);
         ngx_add_timer(s->connection->read, pcf->timeout);
         ngx_del_timer(c->read);
 
         c->log->action = NULL;
         ngx_log_error(NGX_LOG_INFO, c->log, 0, "client logged in");
 
-        ngx_imap_proxy_handler(s->connection->write);
+        ngx_mail_proxy_handler(s->connection->write);
 
         return;
 
@@ -435,7 +446,7 @@ ngx_imap_proxy_pop3_handler(ngx_event_t 
          * we treat the incomplete sending as NGX_ERROR
          * because it is very strange here
          */
-        ngx_imap_proxy_internal_server_error(s);
+        ngx_mail_proxy_internal_server_error(s);
         return;
     }
 
@@ -445,29 +456,175 @@ ngx_imap_proxy_pop3_handler(ngx_event_t 
 
 
 static void
-ngx_imap_proxy_dummy_handler(ngx_event_t *wev)
+ngx_mail_proxy_smtp_handler(ngx_event_t *rev)
+{
+    u_char                    *p;
+    ngx_int_t                  rc;
+    ngx_str_t                  line;
+    ngx_connection_t          *c;
+    ngx_mail_session_t        *s;
+    ngx_mail_proxy_conf_t     *pcf;
+    ngx_mail_core_srv_conf_t  *cscf;
+
+    ngx_log_debug0(NGX_LOG_DEBUG_MAIL, rev->log, 0,
+                   "mail proxy smtp auth handler");
+
+    c = rev->data;
+    s = c->data;
+
+    if (rev->timedout) {
+        ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT,
+                      "upstream timed out");
+        c->timedout = 1;
+        ngx_mail_proxy_internal_server_error(s);
+        return;
+    }
+
+    rc = ngx_mail_proxy_read_response(s, s->mail_state);
+
+    if (rc == NGX_AGAIN) {
+        return;
+    }
+
+    if (rc == NGX_ERROR) {
+        ngx_mail_proxy_upstream_error(s);
+        return;
+    }
+
+    switch (s->mail_state) {
+
+    case ngx_smtp_start:
+        ngx_log_debug0(NGX_LOG_DEBUG_MAIL, rev->log, 0, "mail proxy send ehlo");
+
+        s->connection->log->action = "sending HELO/EHLO to upstream";
+
+        cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module);
+
+        line.len = sizeof("HELO ")  - 1 + cscf->server_name.len + 2;
+        line.data = ngx_palloc(c->pool, line.len);
+        if (line.data == NULL) {
+            ngx_mail_proxy_internal_server_error(s);
+            return;
+        }
+
+        pcf = ngx_mail_get_module_srv_conf(s, ngx_mail_proxy_module);
+
+        p = ngx_cpymem(line.data,
+                       ((s->esmtp || pcf->xclient) ? "EHLO " : "HELO "),
+                       sizeof("HELO ") - 1);
+
+        p = ngx_cpymem(p, cscf->server_name.data, cscf->server_name.len);
+        *p++ = CR; *p = LF;
+
+        s->mail_state = pcf->xclient ? ngx_smtp_helo: ngx_smtp_noxclient;
+
+        break;
+
+    case ngx_smtp_helo:
+        ngx_log_debug0(NGX_LOG_DEBUG_MAIL, rev->log, 0,
+                       "mail proxy send xclient");
+
+        s->connection->log->action = "sending XCLIENT to upstream";
+
+        line.len = sizeof("XCLIENT PROTO=SMTP HELO= ADDR= LOGIN= "
+                          "NAME=[UNAVAILABLE]" CRLF) - 1
+                   + s->esmtp + s->smtp_helo.len
+                   + s->connection->addr_text.len + s->login.len;
+
+        line.data = ngx_palloc(c->pool, line.len);
+        if (line.data == NULL) {
+            ngx_mail_proxy_internal_server_error(s);
+            return;
+        }
+
+        if (s->smtp_helo.len) {
+            line.len = ngx_sprintf(line.data,
+                           "XCLIENT PROTO=%sSMTP HELO=%V ADDR=%V LOGIN=%V "
+                           "NAME=[UNAVAILABLE]" CRLF,
+                           (s->esmtp ? "E" : ""), &s->smtp_helo,
+                           &s->connection->addr_text, &s->login)
+                       - line.data;
+        } else {
+            line.len = ngx_sprintf(line.data,
+                           "XCLIENT PROTO=SMTP ADDR=%V LOGIN=%V "
+                           "NAME=[UNAVAILABLE]" CRLF,
+                           &s->connection->addr_text, &s->login)
+                       - line.data;
+        }
+
+        s->mail_state = ngx_smtp_xclient;
+        break;
+
+    case ngx_smtp_noxclient:
+    case ngx_smtp_xclient:
+
+        ngx_memcpy(s->proxy->buffer->start, smtp_ok, sizeof(smtp_ok) - 1);
+
+        s->proxy->buffer->pos = s->proxy->buffer->start;
+        s->proxy->buffer->last = s->proxy->buffer->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;
+        c->write->handler = ngx_mail_proxy_handler;
+
+        pcf = ngx_mail_get_module_srv_conf(s, ngx_mail_proxy_module);
+        ngx_add_timer(s->connection->read, pcf->timeout);
+        ngx_del_timer(c->read);
+
+        c->log->action = NULL;
+        ngx_log_error(NGX_LOG_INFO, c->log, 0, "client logged in");
+
+        ngx_mail_proxy_handler(s->connection->write);
+
+        return;
+
+    default:
+#if (NGX_SUPPRESS_WARN)
+        line.len = 0;
+        line.data = NULL;
+#endif
+        break;
+    }
+
+    if (c->send(c, line.data, line.len) < (ssize_t) line.len) {
+        /*
+         * we treat the incomplete sending as NGX_ERROR
+         * because it is very strange here
+         */
+        ngx_mail_proxy_internal_server_error(s);
+        return;
+    }
+
+    s->proxy->buffer->pos = s->proxy->buffer->start;
+    s->proxy->buffer->last = s->proxy->buffer->start;
+}
+
+
+static void
+ngx_mail_proxy_dummy_handler(ngx_event_t *wev)
 {
     ngx_connection_t    *c;
-    ngx_imap_session_t  *s;
+    ngx_mail_session_t  *s;
 
-    ngx_log_debug0(NGX_LOG_DEBUG_IMAP, wev->log, 0, "imap proxy dummy handler");
+    ngx_log_debug0(NGX_LOG_DEBUG_MAIL, wev->log, 0, "mail proxy dummy handler");
 
     if (ngx_handle_write_event(wev, 0) == NGX_ERROR) {
         c = wev->data;
         s = c->data;
 
-        ngx_imap_proxy_close_session(s);
+        ngx_mail_proxy_close_session(s);
     }
 }
 
 
 static ngx_int_t
-ngx_imap_proxy_read_response(ngx_imap_session_t *s, ngx_uint_t state)
+ngx_mail_proxy_read_response(ngx_mail_session_t *s, ngx_uint_t state)
 {
     u_char                 *p;
     ssize_t                 n;
     ngx_buf_t              *b;
-    ngx_imap_proxy_conf_t  *pcf;
+    ngx_mail_proxy_conf_t  *pcf;
 
     s->connection->log->action = "reading response from upstream";
 
@@ -504,12 +661,15 @@ ngx_imap_proxy_read_response(ngx_imap_se
 
     p = b->pos;
 
-    if (s->protocol == NGX_IMAP_POP3_PROTOCOL) {
+    switch (s->protocol) {
+
+    case NGX_MAIL_POP3_PROTOCOL:
         if (p[0] == '+' && p[1] == 'O' && p[2] == 'K') {
             return NGX_OK;
         }
+        break;
 
-    } else {
+    case NGX_MAIL_IMAP_PROTOCOL:
         switch (state) {
 
         case ngx_imap_start:
@@ -534,9 +694,31 @@ ngx_imap_proxy_read_response(ngx_imap_se
             }
             break;
         }
+
+        break;
+
+    default: /* NGX_MAIL_SMTP_PROTOCOL */
+        switch (state) {
+
+        case ngx_smtp_helo:
+        case ngx_smtp_noxclient:
+	    if (p[0] == '2' && p[1] == '5' && p[2] == '0') {
+		return NGX_OK;
+	    }
+	    break;
+
+        case ngx_smtp_start:
+        case ngx_smtp_xclient:
+	    if (p[0] == '2' && p[1] == '2' && p[2] == '0') {
+		return NGX_OK;
+	    }
+	    break;
+        }
+
+	break;
     }
 
-    pcf = ngx_imap_get_module_srv_conf(s, ngx_imap_proxy_module);
+    pcf = ngx_mail_get_module_srv_conf(s, ngx_mail_proxy_module);
 
     if (pcf->pass_error_message == 0) {
         *(b->last - 2) = '\0';
@@ -559,7 +741,7 @@ ngx_imap_proxy_read_response(ngx_imap_se
 
 
 static void
-ngx_imap_proxy_handler(ngx_event_t *ev)
+ngx_mail_proxy_handler(ngx_event_t *ev)
 {
     char                   *action, *recv_action, *send_action;
     size_t                  size;
@@ -567,8 +749,8 @@ ngx_imap_proxy_handler(ngx_event_t *ev)
     ngx_buf_t              *b;
     ngx_uint_t              do_write;
     ngx_connection_t       *c, *src, *dst;
-    ngx_imap_session_t     *s;
-    ngx_imap_proxy_conf_t  *pcf;
+    ngx_mail_session_t     *s;
+    ngx_mail_proxy_conf_t  *pcf;
 
     c = ev->data;
     s = c->data;
@@ -586,7 +768,7 @@ ngx_imap_proxy_handler(ngx_event_t *ev)
                           "upstream timed out");
         }
 
-        ngx_imap_proxy_close_session(s);
+        ngx_mail_proxy_close_session(s);
         return;
     }
 
@@ -625,8 +807,8 @@ ngx_imap_proxy_handler(ngx_event_t *ev)
 
     do_write = ev->write ? 1 : 0;
 
-    ngx_log_debug3(NGX_LOG_DEBUG_IMAP, ev->log, 0,
-                   "imap proxy handler: %d, #%d > #%d",
+    ngx_log_debug3(NGX_LOG_DEBUG_MAIL, ev->log, 0,
+                   "mail proxy handler: %d, #%d > #%d",
                    do_write, src->fd, dst->fd);
 
     for ( ;; ) {
@@ -641,7 +823,7 @@ ngx_imap_proxy_handler(ngx_event_t *ev)
                 n = dst->send(dst, b->pos, size);
 
                 if (n == NGX_ERROR) {
-                    ngx_imap_proxy_close_session(s);
+                    ngx_mail_proxy_close_session(s);
                     return;
                 }
 
@@ -693,100 +875,101 @@ ngx_imap_proxy_handler(ngx_event_t *ev)
         ngx_log_error(NGX_LOG_INFO, c->log, 0, "proxied session done");
         c->log->action = action;
 
-        ngx_imap_proxy_close_session(s);
+        ngx_mail_proxy_close_session(s);
         return;
     }
 
     if (ngx_handle_write_event(dst->write, 0) == NGX_ERROR) {
-        ngx_imap_proxy_close_session(s);
+        ngx_mail_proxy_close_session(s);
         return;
     }
 
     if (ngx_handle_read_event(dst->read, 0) == NGX_ERROR) {
-        ngx_imap_proxy_close_session(s);
+        ngx_mail_proxy_close_session(s);
         return;
     }
 
     if (ngx_handle_write_event(src->write, 0) == NGX_ERROR) {
-        ngx_imap_proxy_close_session(s);
+        ngx_mail_proxy_close_session(s);
         return;
     }
 
     if (ngx_handle_read_event(src->read, 0) == NGX_ERROR) {
-        ngx_imap_proxy_close_session(s);
+        ngx_mail_proxy_close_session(s);
         return;
     }
 
     if (c == s->connection) {
-        pcf = ngx_imap_get_module_srv_conf(s, ngx_imap_proxy_module);
+        pcf = ngx_mail_get_module_srv_conf(s, ngx_mail_proxy_module);
         ngx_add_timer(c->read, pcf->timeout);
     }
 }
 
 
 static void
-ngx_imap_proxy_upstream_error(ngx_imap_session_t *s)
+ngx_mail_proxy_upstream_error(ngx_mail_session_t *s)
 {
     if (s->proxy->upstream.connection) {
-        ngx_log_debug1(NGX_LOG_DEBUG_IMAP, s->connection->log, 0,
-                       "close imap proxy connection: %d",
+        ngx_log_debug1(NGX_LOG_DEBUG_MAIL, s->connection->log, 0,
+                       "close mail proxy connection: %d",
                        s->proxy->upstream.connection->fd);
 
         ngx_close_connection(s->proxy->upstream.connection);
     }
 
     if (s->out.len == 0) {
-        ngx_imap_session_internal_server_error(s);
+        ngx_mail_session_internal_server_error(s);
         return;
     }
 
     s->quit = 1;
-    ngx_imap_send(s->connection->write);
+    ngx_mail_send(s->connection->write);
 }
 
 
 static void
-ngx_imap_proxy_internal_server_error(ngx_imap_session_t *s)
+ngx_mail_proxy_internal_server_error(ngx_mail_session_t *s)
 {
     if (s->proxy->upstream.connection) {
-        ngx_log_debug1(NGX_LOG_DEBUG_IMAP, s->connection->log, 0,
-                       "close imap proxy connection: %d",
+        ngx_log_debug1(NGX_LOG_DEBUG_MAIL, s->connection->log, 0,
+                       "close mail proxy connection: %d",
                        s->proxy->upstream.connection->fd);
 
         ngx_close_connection(s->proxy->upstream.connection);
     }
 
-    ngx_imap_session_internal_server_error(s);
+    ngx_mail_session_internal_server_error(s);
 }
 
 
 static void
-ngx_imap_proxy_close_session(ngx_imap_session_t *s)
+ngx_mail_proxy_close_session(ngx_mail_session_t *s)
 {
     if (s->proxy->upstream.connection) {
-        ngx_log_debug1(NGX_LOG_DEBUG_IMAP, s->connection->log, 0,
-                       "close imap proxy connection: %d",
+        ngx_log_debug1(NGX_LOG_DEBUG_MAIL, s->connection->log, 0,
+                       "close mail proxy connection: %d",
                        s->proxy->upstream.connection->fd);
 
         ngx_close_connection(s->proxy->upstream.connection);
     }
 
-    ngx_imap_close_connection(s->connection);
+    ngx_mail_close_connection(s->connection);
 }
 
 
 static void *
-ngx_imap_proxy_create_conf(ngx_conf_t *cf)
+ngx_mail_proxy_create_conf(ngx_conf_t *cf)
 {
-    ngx_imap_proxy_conf_t  *pcf;
+    ngx_mail_proxy_conf_t  *pcf;
 
-    pcf = ngx_pcalloc(cf->pool, sizeof(ngx_imap_proxy_conf_t));
+    pcf = ngx_pcalloc(cf->pool, sizeof(ngx_mail_proxy_conf_t));
     if (pcf == NULL) {
         return NGX_CONF_ERROR;
     }
 
     pcf->enable = NGX_CONF_UNSET;
     pcf->pass_error_message = NGX_CONF_UNSET;
+    pcf->xclient = NGX_CONF_UNSET;
     pcf->buffer_size = NGX_CONF_UNSET_SIZE;
     pcf->timeout = NGX_CONF_UNSET_MSEC;
 
@@ -795,13 +978,14 @@ ngx_imap_proxy_create_conf(ngx_conf_t *c
 
 
 static char *
-ngx_imap_proxy_merge_conf(ngx_conf_t *cf, void *parent, void *child)
+ngx_mail_proxy_merge_conf(ngx_conf_t *cf, void *parent, void *child)
 {
-    ngx_imap_proxy_conf_t *prev = parent;
-    ngx_imap_proxy_conf_t *conf = child;
+    ngx_mail_proxy_conf_t *prev = parent;
+    ngx_mail_proxy_conf_t *conf = child;
 
     ngx_conf_merge_value(conf->enable, prev->enable, 0);
     ngx_conf_merge_value(conf->pass_error_message, prev->pass_error_message, 0);
+    ngx_conf_merge_value(conf->xclient, prev->xclient, 1);
     ngx_conf_merge_size_value(conf->buffer_size, prev->buffer_size,
                               (size_t) ngx_pagesize);
     ngx_conf_merge_msec_value(conf->timeout, prev->timeout, 24 * 60 * 60000);