--- a/src/mail/ngx_mail_core_module.c
+++ b/src/mail/ngx_mail_core_module.c
@@ -288,19 +288,12 @@ ngx_mail_core_listen(ngx_conf_t *cf, ngx
 {
     ngx_mail_core_srv_conf_t  *cscf = conf;
 
-    size_t                      len, off;
-    in_port_t                   port;
     ngx_str_t                  *value;
     ngx_url_t                   u;
     ngx_uint_t                  i, m;
-    struct sockaddr            *sa;
     ngx_mail_listen_t          *ls;
     ngx_mail_module_t          *module;
-    struct sockaddr_in         *sin;
     ngx_mail_core_main_conf_t  *cmcf;
-#if (NGX_HAVE_INET6)
-    struct sockaddr_in6        *sin6;
-#endif
 
     value = cf->args->elts;
 
@@ -325,49 +318,13 @@ ngx_mail_core_listen(ngx_conf_t *cf, ngx
 
     for (i = 0; i < cmcf->listen.nelts; i++) {
 
-        sa = &ls[i].u.sockaddr;
-
-        if (sa->sa_family != u.family) {
-            continue;
-        }
-
-        switch (sa->sa_family) {
-
-#if (NGX_HAVE_INET6)
-        case AF_INET6:
-            off = offsetof(struct sockaddr_in6, sin6_addr);
-            len = 16;
-            sin6 = &ls[i].u.sockaddr_in6;
-            port = ntohs(sin6->sin6_port);
-            break;
-#endif
-
-#if (NGX_HAVE_UNIX_DOMAIN)
-        case AF_UNIX:
-            off = offsetof(struct sockaddr_un, sun_path);
-            len = sizeof(((struct sockaddr_un *) sa)->sun_path);
-            port = 0;
-            break;
-#endif
-
-        default: /* AF_INET */
-            off = offsetof(struct sockaddr_in, sin_addr);
-            len = 4;
-            sin = &ls[i].u.sockaddr_in;
-            port = ntohs(sin->sin_port);
-            break;
-        }
-
-        if (ngx_memcmp(ls[i].u.sockaddr_data + off, u.sockaddr + off, len)
-            != 0)
+        if (ngx_cmp_sockaddr(&ls[i].u.sockaddr, ls[i].socklen,
+                             (struct sockaddr *) &u.sockaddr, u.socklen, 1)
+            != NGX_OK)
         {
             continue;
         }
 
-        if (port != u.port) {
-            continue;
-        }
-
         ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                            "duplicate \"%V\" address and port pair", &u.url);
         return NGX_CONF_ERROR;
@@ -434,11 +391,10 @@ ngx_mail_core_listen(ngx_conf_t *cf, ngx
 
         if (ngx_strncmp(value[i].data, "ipv6only=o", 10) == 0) {
 #if (NGX_HAVE_INET6 && defined IPV6_V6ONLY)
+            size_t  len;
             u_char  buf[NGX_SOCKADDR_STRLEN];
 
-            sa = &ls->u.sockaddr;
-
-            if (sa->sa_family == AF_INET6) {
+            if (ls->u.sockaddr.sa_family == AF_INET6) {
 
                 if (ngx_strcmp(&value[i].data[10], "n") == 0) {
                     ls->ipv6only = 1;
@@ -456,7 +412,7 @@ ngx_mail_core_listen(ngx_conf_t *cf, ngx
                 ls->bind = 1;
 
             } else {
-                len = ngx_sock_ntop(sa, ls->socklen, buf,
+                len = ngx_sock_ntop(&ls->u.sockaddr, ls->socklen, buf,
                                     NGX_SOCKADDR_STRLEN, 1);
 
                 ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,