using System.Text;
using RabbitMQ.Client;

Random rand = new Random();
var factory = new ConnectionFactory { HostName = "localhost" };
using var connection = factory.CreateConnection();
using var channel = connection.CreateModel();

channel.ExchangeDeclare(exchange: "post", type: ExchangeType.Fanout);

foreach (var item in Enumerable.Range(0, 1000))
{
    var message = rand.Next().ToString();

    var body = Encoding.UTF8.GetBytes(message);
    channel.BasicPublish(exchange: "post",
            routingKey: string.Empty,
            basicProperties: null,
            body: body);

    Console.WriteLine($" [x] Письмо готово {message}");
    await Task.Delay(500);
}

Console.WriteLine(" Нажми [enter] чтобы выйти.");
Console.ReadLine();

static string GetMessage(string[] args)
{
    return ((args.Length > 0) ? string.Join(" ", args) : "info: Привет Мир!");
}