How Do I Send Email In C# With Gmail Id

This is the class I use:

using System;
using System.Collections;
using System.Collections.Generic;
using System.Data;
using System.Diagnostics;
using System.Configuration;
using System.Web;
using System.Net.Mail;
using System.ComponentModel;
using System.Net;
using System.Security.Cryptography.X509Certificates;
using System.Net.Security;

public class EmailRelay
{
    private string smtpServer;
    private string userName;
    private string password;
    private SmtpClient smtp;
    private int connectionLimit;

    public class threadStatus
    {
        public string msg;
        public bool succeeded;
        public string id;
        public string subject;
    }

    public EmailRelay(string _smtpServer, string _userName, string _password, bool useSSL = true, Int16 port = 0, int _connectionLimit = 6)
    {
        smtpServer                          = _smtpServer;
        userName                            = _userName;
        password                            = _password;
        connectionLimit                     = _connectionLimit;
        NetworkCredential NetworkCred       = new System.Net.NetworkCredential(userName , password);

        if (useSSL)
            { if (port == 0) { port = 587; } }
        else
            { if (port == 0) { port = 25;  } }

        System.Net.ServicePointManager.MaxServicePoints = 100;

        smtp                            = new SmtpClient(smtpServer, port);
        smtp.EnableSsl                  = useSSL;
        smtp.UseDefaultCredentials      = true;
        smtp.Credentials                = NetworkCred;

        // Performance tweaks:  
        if (connectionLimit < 10)
        {
            smtp.ServicePoint.MaxIdleTime = (connectionLimit * 6);
        }
        else if (connectionLimit < 20)
        {
            smtp.ServicePoint.MaxIdleTime = (connectionLimit * 2000);
        }
        else
        {
            smtp.ServicePoint.MaxIdleTime = 60000;
        }
        
        smtp.ServicePoint.ConnectionLimit = connectionLimit;
    }

    public bool ServerCertificateValidationCallback(object sender, X509Certificate cert, X509Chain chain, SslPolicyErrors sslPolicyErrors)
    {
        return sslPolicyErrors == System.Net.Security.SslPolicyErrors.None;
    }

    public void ConnectionLimit(int value)
    {
        connectionLimit = value;
        smtp.ServicePoint.ConnectionLimit = connectionLimit;
    }

    public bool SendMail(string fromAddress, string toAddress, string subject, 
                         string body, ref string errMsg, string fromEmailName = "")
    {

        MailMessage mm                  = new MailMessage();
        MailAddress emailFrom           = new MailAddress(fromAddress, fromEmailName);

        try
        {
            mm.To.Add(new MailAddress(toAddress));
            mm.From                     = emailFrom;
            mm.Subject                  = subject;
            mm.Body                     = body;
            mm.IsBodyHtml               = true;

            smtp.Send(mm);
            mm.Dispose();
        }
        catch (Exception ex)
        {
            errMsg = ex.Message;
            if (!(ex.InnerException == null)) { errMsg += " (" + ex.InnerException.Message + ")"; }
            return false;
        }

        return true;
    }

    public void Close()
    {
        smtp.Dispose();
    }
}

Used like this:

EmailRelay thisMailer = new EmailRelay("server name", "user@gmail.com", "password", useSslOrNotBool, portNumber);

thisMailer.SendMail("from@whatever.com", "to@whatever.com", "Email subject", "Email Body - use html", ref errMsg, "From friendly name");

Set _connectionLimit higher then 6 in the constructor if you are using multithreding to increase performance while sending multiple mails. The higher _connectionLimit is, the faster you will be able to send mails.

But fair warning: gmail has sending limits, and according to their documentation will accept about 1 mail per second. If you send too many faster then that, they will cut you off for a while.

-Pete

http://stackoverflow.com/questions/32260/sending-email-in-net-through-gmail[^]