Sending Emails from C# Application using default SMTP

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Screenshot - SendMail.jpg

Introduction

This article is provide a demo for how we can send Emails from a C# Windows Application.

Description

First add the reference from project-->Add References then select System.Web.dll. Then include using System.Web.Mail in your class and create MailMessage object and assign values to all required properties.

MailMessage objMsg=new MailMessage();

if(ValidateEmail(txtTo.Text)==true) objMsg.To=txtTo.Text;

else throw new MyExp();

objMsg.From=sFrom;

if (txtCc.Text!="") objMsg.Bcc=txtBcc.Text;

if (txtBcc.Text!="") objMsg.Cc=txtCc.Text;

if (txtSubject.Text!="") objMsg.Subject=txtSubject.Text;

else throw new MyExp();

objMsg.Body=txtMessage.Text;

You can send attachments also with your mails. For that we can use MailAttachment Object like :

MailAttachment attach1;
string sFile;
if(lstfiles.Items.Count>0)
{
    for(int i=0;i<lstfiles.Items.Count;i++)
    {
        lstfiles.SelectedIndex=i;
        sFile=lstfiles.Text;
        attach1=new MailAttachment(sFile);
        objMsg.Attachments.Add(attach1);
    }
}

But before sending the mail you have to set From field by clicking From Button and Smtp Server, if you are using it on Windows 2000, Windows XP Professional, Windows Server 2003 and have a configured smtp server then you can leave it blank.

Then you can send the mail by clicking Send Button.

SmtpMail.Send(objMsg);

Also when you run this application it will show in System tray and when you right click on that icon it will show the popup menu.

mymenu=new ContextMenu();

mymenu.MenuItems.Add("Open",new System.EventHandler(open_Click));

mymenu.MenuItems.Add("Hide",new System.EventHandler(hide_Click));

mymenu.MenuItems.Add("Exit",new System.EventHandler(exit_Click));

myIcon=new NotifyIcon();

myIcon.Text="Right Click For Context Menu";

myIcon.Visible=true;

myIcon.Icon=new Icon(GetType(),"MAIL6.ICO");

myIcon.ContextMenu=mymenu;

This above image show the popup at System tray, from where we can Hide,Open and Exit the Application.

Complete Source Code

using System;

using System.Drawing;

using System.Collections;

using System.ComponentModel;

using System.Windows.Forms;

using System.Data;

using System.Web.Mail;

using System.Text.RegularExpressions;

using MailOpt;

namespace MailTest

{

public class SendMail : System.Windows.Forms.Form

{

    private System.Windows.Forms.TextBox txtBcc;

    private System.Windows.Forms.Label label1;

    private System.Windows.Forms.Label label2;

    private System.Windows.Forms.Label label3;

    private System.Windows.Forms.Label label4;

    private System.Windows.Forms.Label label5;

    private System.Windows.Forms.Label label6;

    private System.Windows.Forms.Button button3;

    private System.Windows.Forms.Label label7;

    private System.Windows.Forms.OpenFileDialog dlgopenFile;

    private System.Windows.Forms.Button btnshowfile;

    private System.Windows.Forms.TextBox txtAttachment;

    private System.Windows.Forms.TextBox txtTo;

    private System.Windows.Forms.TextBox txtSubject;

    private System.Windows.Forms.TextBox txtCc;

    private System.Windows.Forms.RichTextBox txtMessage;

    private System.Windows.Forms.ListBox lstfiles;

    private System.Windows.Forms.Button btnSend;

    int c=0;

    public static string sFrom="";

    public static string sSmtpServer="";

    private System.Windows.Forms.Button btnFrom;

    NotifyIcon myIcon;

    ContextMenu mymenu;

    private System.ComponentModel.Container components = null;

    public SendMail()

    {

    InitializeComponent();

    }

    protected override void Dispose( bool disposing )

    {

        if( disposing )

        {

            if(disposing)

            {

                this.myIcon.Dispose();

            }

            if (components != null) 

            {

                components.Dispose();

            }

        }

            base.Dispose( disposing );


    }    

    [STAThread]

    static void Main() 

    {

        Application.Run(new SendMail());

    }

    private void btnSend_Click(object sender, System.EventArgs e)

    {

    try

    {

    if (sSmtpServer=="")

    {

    MessageBox.Show("You have not set any SmtpServer name! It will " & _
"use default Mail Server if you configured on your machine","SmtpServer Name Not Found",
MessageBoxButtons.OK,MessageBoxIcon.Information);

btnFrom.Focus();

}

else

{

SmtpMail.SmtpServer=sSmtpServer;

}

if(sFrom=="" || sFrom==<a href="mailto:test@mail.com">test@mail.com</a>)

{

MessageBox.Show("Please set your (Sender's) Address First","Sender Address",
MessageBoxButtons.OK,MessageBoxIcon.Error);

btnFrom.Focus();

return;

}


MailMessage objMsg=new MailMessage();

if(ValidateEmail(txtTo.Text)==true) objMsg.To=txtTo.Text;

else throw new MyExp();

objMsg.From=sFrom;

if (txtCc.Text!="") objMsg.Bcc=txtBcc.Text;

if (txtBcc.Text!="") objMsg.Cc=txtCc.Text;

if (txtSubject.Text!="") objMsg.Subject=txtSubject.Text;

else throw new MyExp();

objMsg.Body=txtMessage.Text;

MailAttachment attach1;//, attach2, attach3;

string sFile;

if(lstfiles.Items.Count>0)

{

for(int i=0;i<lstfiles.Items.Count;i++)

{

lstfiles.SelectedIndex=i;

sFile=lstfiles.Text;

attach1=new MailAttachment(sFile);

objMsg.Attachments.Add(attach1);

}

}

SmtpMail.Send(objMsg); 

lstfiles.Items.Clear();

MessageBox.Show("Mail Sent");

}

catch(Exception ex)

{

MessageBox.Show("Error :"+ex.ToString()); 

}

}

private void btnshowfile_Click(object sender, System.EventArgs e)

{

dlgopenFile.ShowDialog();

txtAttachment.Text=dlgopenFile.FileName;

lstfiles.Items.Add (txtAttachment.Text);

}

private void button3_Click(object sender, System.EventArgs e)

{

Environment.Exit(0);

}

private void SendMail_Load(object sender, System.EventArgs e)

{

mymenu=new ContextMenu();

mymenu.MenuItems.Add("Open",new System.EventHandler(open_Click));

mymenu.MenuItems.Add("Hide",new System.EventHandler(hide_Click));

mymenu.MenuItems.Add("Exit",new System.EventHandler(exit_Click));

myIcon=new NotifyIcon();

myIcon.Text="Right Click For Context Menu";

myIcon.Visible=true;

myIcon.Icon=new Icon(GetType(),"MAIL6.ICO");

myIcon.ContextMenu=mymenu;

}

protected void exit_Click(Object sender, System.EventArgs e) 

{

Close();

}

protected void hide_Click(Object sender, System.EventArgs e) 

{

Hide();

}

protected void open_Click(Object sender, System.EventArgs e) 

{

Show();

}


public bool ValidateEmail(string sEmail)

{

Regex exp=new Regex(@"\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*");

Match m=exp.Match(sEmail);

if(m.Success && m.Value.Equals(sEmail)) return true;

else return false;

}


private void btnFrom_Click(object sender, System.EventArgs e)

{

MailOpt.frmFrom frm=new MailOpt.frmFrom();

frm.Show();

}

}

class MyExp: Exception

{

public override string ToString()

{

return " Value is Blank or Invalid";

}

}

}


//Other frmForm.cs


using System;

using System.Drawing;

using System.Collections;

using System.ComponentModel;

using System.Windows.Forms;

using MailTest;

namespace MailOpt

{

public class frmFrom : System.Windows.Forms.Form

{

private System.Windows.Forms.TextBox txtFrom;

private System.Windows.Forms.Label label1;

private System.Windows.Forms.Button btnok;

private System.Windows.Forms.Button button1;

private System.Windows.Forms.TextBox txtSmtpServer;

private System.Windows.Forms.Label label2;

private System.ComponentModel.Container components = null;

public frmFrom()

{

InitializeComponent();

}

protected override void Dispose( bool disposing )

{

if( disposing )

{

if(components != null)

{

components.Dispose();

}

}

base.Dispose( disposing );

}


#region Windows Form Designer generated code

#endregion

private void btnok_Click(object sender, System.EventArgs e)

{

SendMail.sFrom=txtFrom.Text;

SendMail.sSmtpServer=txtSmtpServer.Text;

Dispose();

}

private void button1_Click(object sender, System.EventArgs e)

{

Dispose();

}

}

}

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

About the Author

Rajan2may

Web Developer

United States

Member

Working as Consultant with Merrill Lynch, New York

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Email Component

Gregory Nozik

15:00 28 Sep '11

Good article. I encapsulated sending email component in separate component. Component supports Google,Hotmail accounts, exception handling,attachments. You can read it in my blog http://gregnozik.blogspot.com/2011/09/send-email-easily.html
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My vote of 4

jorge acevedo

4:00 16 Aug '10

is very easy to understand and follow, only constrain is that is not updated to 2010 and system.web is now obsolete
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Getting Error

sansar

0:24 15 Feb '08

This example is very fine.
if i run this application it is giving following error.
Error: The server rejected one or more recipient address.The server response was:550 Domain does not exist;please check your spelling. Le domaine n'existe pas; veuillez verifier votre epellation. El dominio no existe; compruebe por favor su deletreo.

can you tell me how to solve this problem.
my email id: sarla.shankar@gmail.com

Thanx in advance

Kay says there's a potential bug

Sean Ewington

8:55 4 Jun '07

"There is a potential bug in the code. Around where he sets up the CC and Bcc fields.. the text boxes are mismatched" - Kay
Sign In·View Thread·Permalink	1.00/5 (1 vote)

azmiralda12

3:17 28 Dec '06


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SMTP username/password

shabonaa

10:48 1 Dec '06

how can i set the username and password
Sign In·View Thread·Permalink	1.60/5 (15 votes)

SMTP

GKT

12:44 19 May '06

Hello Rajan2May:
I was wondering I have SMTP on a standalone Windows XP Pro machine(not part of a domain)
Microsoft Hotmail refused to except email from my standalone SMTP it returned error code 220 (as found in the SMTP logs ) it somehow think this is spam, how would you supply credentials to SMTP to allow Microsoft site to except this email? Could the ISPs credentials somehow be used ?

Thanks
Glenn

Can not access CDO.Message

canhga

23:09 18 Sep '05

Thank you for the program. But I got an error: "Can not access CDO.Message" I have set smtp server corectly (working well with Oulook Express) Do you know why? Thanh you! canhga
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Re: Can not access CDO.Message

anzac

10:40 5 Dec '05

Ensure you've registered cdosys.dll properly. Also, if you're running SMTP on a local box, use 'localhost' as the SMTP server. Those are the only issues I experienced when running this sample application. ~~cj -- modified at 16:47 Monday 5th December, 2005
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Re: Not robust enough

Rajan2May

17:59 14 Sep '04

Hi, Its my first article I have written for any web site and I am just trying how to post the article, But definetly I will made some improvement to this. Thanks for valuable suggestions.
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XP Home

mxmissile

9:48 14 Sep '04

The mechanism that System.Web.Mail uses is not available to applications running on XP Home (without some hacking at least). So what if I am using XP Home? Please provide some insight.
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Re: XP Home

Heath Stewart

10:42 21 Sep '04

XP Home does not implement a CDO server and you will get an exception, as discussed in a previous reply[^].

Sending mail messages using SMTP is very simple, however. Take a look at http://www.ietf.org/rfc/rfc0821.txt[^] or search this site for other articles or comments in forums. I, for one, have posted many times an example for sending SMTP messages that don't rely on any library installed on the user's system. It's quite simple, especially for simple mail messages (mime-multipart gets a little complicated, but nothing too difficult).

The most difficult situation in this case is finding the MX record, which is the mail exchange record. I have posted code for that before here[^].

This posting is provided "AS IS" with no warranties, and confers no rights.

Software Design Engineer
Developer Division Sustained Engineering
Microsoft

[My Articles]

Not robust enough

mav.northwind

20:42 13 Sep '04

Rajan, you're only showing the very easy, straight way to send email with the very basic functions of SmtpMail, but that won't work in many cases.
First, SmtpMail only works on Win2000 prof, WinXP prof and Win 2003 server (as it relies on CDO). Try it on XP HOME for example and enjoy a happy HttpException... Frown | :(

Second, by not giving an SmtpServer to SmtpMail, the standard mail queueing in Win2000 is used in the cases where the code actually works. I'd say most Win2000 PC's are _not_ configured for mail relay, so the mail will seem to get sent but will remain on the local pc's harddisk forever.
Third, you're completely omitting the case where the target SmtpServer requires authorization. Not many servers out there let you send mail without saying who you are.
Fourth, the way you're handling the attachments is _really_ bad programming style. Lots of copy&paste, only 3 attachments possible for no reason, three if for three different numbers of attachments, setting the SelectedIndex in order to use ListBox.Text,...
I think you can do better than this!

In my opinion you'll have to add some work to this article to make it useful.

mav