how can we send bulk email using asp.net core console app?

using System.Net;
using System.Net.Mail;

void SendEmailsUsingSmtp(List emails)
{
    string smtpServer = "your.smtp.server";
    int smtpPort = 587; // Update with your SMTP port
    string smtpUsername = "your.smtp.username";
    string smtpPassword = "your.smtp.password";

    using (SmtpClient client = new SmtpClient(smtpServer, smtpPort))
    {
        client.Credentials = new NetworkCredential(smtpUsername, smtpPassword);
        client.EnableSsl = true;

        foreach (string email in emails)
        {
            using (MailMessage message = new MailMessage())
            {
                message.From = new MailAddress("[email protected]");
                message.To.Add(email);
                message.Subject = "Your Email Subject";
                message.Body = "Your Email Body";

                try
                {
                    client.Send(message);
                    Console.WriteLine($"Email sent to: {email}");
                }
                catch (Exception ex)
                {
                    Console.WriteLine($"Error sending email to {email}: {ex.Message}");
                }
            }
        }
    }
}

using System;
using System.Collections.Generic;
using SendGrid;
using SendGrid.Helpers.Mail;
using System.Threading.Tasks;

class Program
{
    static async Task Main(string[] args)
    {
        string sendGridApiKey = "your-sendgrid-api-key";

        List recipients = new List
        {
            "[email protected]",
            "[email protected]",
            // ... add more recipients
        };

        await SendBulkEmailAsync(recipients, sendGridApiKey);
    }

    static async Task SendBulkEmailAsync(List recipients, string apiKey)
    {
        var client = new SendGridClient(apiKey);
        var from = new EmailAddress("[email protected]", "Your Name");
        var subject = "Your Subject";
        var plainTextContent = "Your plain text content";
        var htmlContent = "
Your HTML content
";

        foreach (var recipient in recipients)
        {
            var to = new EmailAddress(recipient);
            var msg = MailHelper.CreateSingleEmail(from, to, subject, plainTextContent, htmlContent);
            var response = await client.SendEmailAsync(msg);

            Console.WriteLine($"Email sent to: {recipient}, Response: {response.StatusCode}");
        }
    }
}