--- a/src/mail/ngx_mail_smtp_handler.c
+++ b/src/mail/ngx_mail_smtp_handler.c
@@ -228,7 +228,7 @@ ngx_mail_smtp_greeting(ngx_mail_session_
     timeout = sscf->greeting_delay ? sscf->greeting_delay : cscf->timeout;
     ngx_add_timer(c->read, timeout);
 
-    if (ngx_handle_read_event(c->read, 0) == NGX_ERROR) {
+    if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
         ngx_mail_close_connection(c);
     }
 
@@ -270,7 +270,7 @@ ngx_mail_smtp_invalid_pipelining(ngx_eve
 
         ngx_add_timer(c->read, cscf->timeout);
 
-        if (ngx_handle_read_event(c->read, 0) == NGX_ERROR) {
+        if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
             ngx_mail_close_connection(c);
             return;
         }
@@ -647,8 +647,7 @@ ngx_mail_smtp_mail(ngx_mail_session_t *s
     sscf = ngx_mail_get_module_srv_conf(s, ngx_mail_smtp_module);
 
     if (!(sscf->auth_methods & NGX_MAIL_AUTH_NONE_ENABLED)) {
-        ngx_mail_smtp_log_rejected_command(s, c,
-                                           "client was rejected: \"%V\"");
+        ngx_mail_smtp_log_rejected_command(s, c, "client was rejected: \"%V\"");
 
         s->out.len = sizeof(smtp_auth_required) - 1;
         s->out.data = smtp_auth_required;
@@ -672,13 +671,16 @@ ngx_mail_smtp_mail(ngx_mail_session_t *s
 
     s->smtp_from.len = cmd.len;
 
-    s->smtp_from.data = ngx_palloc(c->pool, cmd.len);
+    s->smtp_from.data = ngx_pnalloc(c->pool, cmd.len);
     if (s->smtp_from.data == NULL) {
         return NGX_ERROR;
     }
 
     ngx_memcpy(s->smtp_from.data, cmd.data, cmd.len);
 
+    ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0,
+                   "smtp mail from:\"%V\"", &s->smtp_from);
+
     s->out.len = sizeof(smtp_ok) - 1;
     s->out.data = smtp_ok;
 
@@ -705,13 +707,16 @@ ngx_mail_smtp_rcpt(ngx_mail_session_t *s
 
     s->smtp_to.len = cmd.len;
 
-    s->smtp_to.data = ngx_palloc(c->pool, cmd.len);
+    s->smtp_to.data = ngx_pnalloc(c->pool, cmd.len);
     if (s->smtp_to.data == NULL) {
         return NGX_ERROR;
     }
 
     ngx_memcpy(s->smtp_to.data, cmd.data, cmd.len);
 
+    ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0,
+                   "smtp rcpt to:\"%V\"", &s->smtp_to);
+
     s->auth_method = NGX_MAIL_AUTH_NONE;
 
     return NGX_DONE;
@@ -784,7 +789,7 @@ ngx_mail_smtp_discard_command(ngx_mail_s
     }
 
     if (n == NGX_AGAIN) {
-        if (ngx_handle_read_event(c->read, 0) == NGX_ERROR) {
+        if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
             ngx_mail_session_internal_server_error(s);
             return NGX_ERROR;
         }