Gmail SMTP

public record MailSettings(string Username, string Password, int Port, string FromEmail, string Host);

public class MailService(MailSettings mailConfig)
{
    public async Task SendEmailAsync(string toEmail, string subject, string htmlBody)
    {
        using SmtpClient client = new(mailConfig.Host, mailConfig.Port);
        using MailMessage mail = new(mailConfig.FromEmail, toEmail, subject, htmlBody);

        client.Credentials = new NetworkCredential(mailConfig.Username, mailConfig.Password);
        client.EnableSsl = true;
        mail.IsBodyHtml = true;
        await client.SendMailAsync(mail);
    }
}

MailService mailService = new(
    mailConfig: new MailSettings(
        Username: "YOUR_EMAIL",
        Password: "APP_ID_PASSWORD",
        Port: 587,
        FromEmail: "YOUR_EMAIL",
        Host: "smtp.gmail.com"
    )
);

await mailService.SendEmailAsync(
    toEmail: Email,
    subject: "Subject Line",
    htmlBody: "Email Body in HTML"
);