Сканер портов не может подключиться к хосту

Написал простой сканер портов на асинхронных сокетах. Соединение при сканировании mail.ru и диапазоне [1; 1024] удается установить только на порт 25, дальше не идет. Кусок main():

port_range range; //structure for saving range of ports
(std::cin >> range.from >> range.to).get();
con_list cons; //std::vector of structures with sockets
sockaddr_in server_data;
u_long cmd = 1;
fd_set write;
timeval wait_time = { 0, 0 };
USHORT port = range.from;
server_data.sin_family = AF_INET;
tmp.s_addr = *(u_long*)remote_host_info->h_addr;
inet_pton(AF_INET, (PCSTR)inet_ntoa(tmp), &server_data.sin_addr);
while (true)
{
    //CONNECTION PHASE
    if (port <= range.to)
    {
        SOCKET sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
        server_data.sin_port = htons(port);
        if (sock == INVALID_SOCKET)
        {
            output_error("Couldn't create scan socket");
            finalize(); //WSACleanup(), system("pause")
            return EXIT_FAILURE;
        }
        //else
            //std::cout << "Created" << std::endl;
        if (ioctlsocket(sock, FIONBIO, &cmd) == SOCKET_ERROR)
        {
            error_to_close_cons("Couldn't put the socket in asynchronous mode", cons); //closes all created sockets, clears con_list container
            error_to_close_socket("", sock);
            finalize();
            return EXIT_FAILURE;
        }
        //else
            //std::cout << "Async" << std::endl;
        cons.push_back({ sock, 0, con_mode::write, port, 0, clock() });
        if (connect(sock, (SOCKADDR*)&server_data, sizeof(server_data)) == SOCKET_ERROR)
            if (WSAGetLastError() != WSAEWOULDBLOCK)
            {
                error_to_close_cons("Couldn't connect", cons);
                error_to_close_socket("", sock);
                finalize();
                return EXIT_FAILURE;
            }
        //else
            //std::cout << "Connected" << std::endl;
    }
    port++;
    //SCAN PHASE
    delete_invalid_cons(cons); //deletes structures with INVALID_SOCKET
    FD_ZERO(&write);
    if (cons.empty())
        break;
    for (u_int i = 0; i < cons.size(); i++)
        FD_SET(cons[i].sock, &write);
    if (select(0, NULL, &write, NULL, &wait_time) == SOCKET_ERROR)
    {
        error_to_close_cons("Couldn't perform client loop", cons);
        finalize();
        return EXIT_FAILURE;
    }
    //else
        //std::cout << "Selected" << std::endl;
    for (u_int i = 0; i < cons.size(); i++)
        if (FD_ISSET(cons[i].sock, &write))
        {
            std::cout << "Connection established on port " << cons[i].con_port << " in " << (clock() - cons[i].con_time) / CLOCKS_PER_SEC << " seconds" << std::endl;
            close_socket(cons[i].sock);
            cons[i].sock = INVALID_SOCKET;
        }
        else
        {
            std::cout << "Waiting time exceeded" << std::endl;
            close_socket(cons[i].sock);
            cons[i].sock = INVALID_SOCKET;
        }
        //else
            //std::cout << "Couldn't scan" << std::endl;
}
finalize();
return EXIT_SUCCESS;

}

Кусок заголовочника:

#pragma once
#ifndef WINSOCK_ERROR
#define WINSOCK_ERROR
#include <WinSock2.h>
#include <Windows.h>
#include <iostream>
#include <cstdlib>
#include <vector>
#include <cstring>
#include <ctime>
#define ECHO_PORT 32768
#define WSA_VERSION 0x0202
#define LOCALHOST "127.0.0.1"
#define BUFF_SIZE 8192
#define BACKLOG 4
#define WAIT_TIME 10
#define INPUT_BUFF 16

namespace con_mode
{
    enum mode
    {
        write,
        read,
        input //for client
    };
}
typedef struct async_connection
{
    SOCKET sock;
    int buffer_pos; //position in buffer
    con_mode::mode c_mode; //defines in which mode (recv/send) a socket works (for single-channel applications)
    //char* buffer; //for message from client
    USHORT con_port;
    int address_num; //address number in HOSTENT struct
    clock_t con_time;
} async_connection;
typedef struct port_range
{
    USHORT from;
    USHORT to;
    bool error_flag;
    char* error_message;
} port_range;
typedef std::vector<async_connection> con_list;

Другой сканер при тех же условиях устанавливал соединение на большее число портов.