The following c# example codes demonstrate how to send email with file attachment using SMTP server.
To send an email with file attachment, we need to use AddAttachment method. This method can attach a file to the email message from local disk or a remote URL.
Sections:
Before you can use the following codes, please download EASendMail SMTP Component and install it on your machine at first. Full sample proejcts are included in this installer.
Install from NuGet
You can also install the run-time assembly by NuGet. Run the following command in the NuGet Package Manager Console:
Install-Package EASendMail
Note
If you install it by NuGet, no sample projects are installed, only .NET assembly is installed.
To use EASendMail SMTP Component in your project, the first step is Add reference
of EASendMail to your project
. Please create or open your project with Visual Studio,
then go to menu
-> Project
-> Add Reference
-> .NET
-> Browse...
, and select
Installation Path\Lib\net[version]\EASendMail.dll
from your disk, click Open
-> OK
, the reference of EASendMail
will be added to your project, and you can start to use it to send email
in your project.
Because EASendMail has separate builds for .Net Framework, please refer to the following table and choose the correct dll.
Separate builds of run-time assembly for .NET Framework 2.0, 3.5, 4.0, 4.5, 4.6.1, 4.7.2, 4.8.1, .NET 5.0, .NET 6.0, .NET 7.0, .NET 8.0, .NET Standard 2.0 and .NET Compact Framework 2.0, 3.5.
File | .NET Framework Version |
Lib\[net20|40|45|461|472|481]\EASendMail.dll |
Built with .NET Framework 2.0, 4.0, 4.5, 4.6.1, 4.7.2, 4.8.1
It requires .NET Framework 2.0, 3.5 or later version. |
Lib\[net5.0|6.0|7.0|8.0]\EASendMail.dll |
Built with .NET 5.0, .NET 6.0, .NET 7.0, .NET 8.0
It requires .NET 5.0 or later version. |
Lib\netstandard2.0\EASendMail.dll |
Built with .NET Standard 2.0
It requires .NET Standard 2.0 or later version. |
Lib\[net20-cf|net35-cf]\EASendMail.dll |
Built with .NET Compact Framework 2.0, 3.5
It requires .NET Compact Framework 2.0, 3.5 or later version. |
The following example codes demonstrate sending email with attachment.
In order to run it correctly, please change SMTP server
, user
, password
, sender
, recipient
value to yours.
Note
To get full sample projects, please download and install EASendMail on your machine.
using System;
using System.Collections.Generic;
using System.Text;
// Add EASendMail namespace
using EASendMail;
namespace mysendemail
{
class Program
{
static void Main(string[] args)
{
try
{
SmtpMail oMail = new SmtpMail("TryIt");
// Set sender email address, please change it to yours
oMail.From = "test@emailarchitect.net";
// Set recipient email address, please change it to yours
oMail.To = "support@emailarchitect.net";
// Set email subject
oMail.Subject = "test html email with attachment";
// Set Html body
oMail.HtmlBody = "<font size=\"5\">This is</font> <font color=\"red\"><b>a test</b></font>";
// Add attachment from local disk
oMail.AddAttachment("d:\\test.pdf");
// Add attachment from remote website
oMail.AddAttachment("http://www.emailarchitect.net/webapp/img/logo.jpg");
// Your SMTP server address
SmtpServer oServer = new SmtpServer("smtp.emailarchitect.net");
// User and password for ESMTP authentication, if your server doesn't require
// User authentication, please remove the following codes.
oServer.User = "test@emailarchitect.net";
oServer.Password = "testpassword";
// Most mordern SMTP servers require SSL/TLS connection now.
// ConnectTryTLS means if server supports SSL/TLS, SSL/TLS will be used automatically.
oServer.ConnectType = SmtpConnectType.ConnectTryTLS;
// If your SMTP server uses 587 port
// oServer.Port = 587;
// If your SMTP server requires SSL/TLS connection on 25/587/465 port
// oServer.Port = 25; // 25 or 587 or 465
// oServer.ConnectType = SmtpConnectType.ConnectSSLAuto;
Console.WriteLine("start to send email with attachment ...");
SmtpClient oSmtp = new SmtpClient();
oSmtp.SendMail(oServer, oMail);
Console.WriteLine("email was sent successfully!");
}
catch (Exception ep)
{
Console.WriteLine("failed to send email with the following error:");
Console.WriteLine(ep.Message);
}
}
}
}
TLS is the successor of SSL, more and more SMTP servers require TLS 1.2
encryption now.
If your operating system is Windows XP/Vista/Windows 7/Windows 2003/2008/2008 R2/2012/2012 R2
, you need to
enable TLS 1.2 protocol in your operating system like this:
Enable TLS 1.2 on Windows XP/Vista/7/10/Windows 2008/2008 R2/2012
Appendix
Comments
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