VB.NET - Send Email over TLS on 25 or 587 Port

The following vb.net example codes demonstrate how to send email over TLS on 25 or 587 SMTP port.

SSL and TLS

SSL connection encrypts data between the SMTP component and SMTP server to protects user, password and email content in TCP/IP level. Now this technology is commonly used and many SMTP servers are deployed with SSL such as Gmail, Yahoo and Hotmail. There are two ways to deploy SSL on SMTP server:

  • Explicit SSL (TLS)

    Using STARTTLS command to switch SSL channel on normal SMTP port (25 or 587);

  • Implicit SSL

    Deploying SSL on another port (465 or other port, you may query it from your server administrator

Installation

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.

Add Reference

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 EASendMail{version}.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.

add reference in c#/vb.net/c++/cli/clr

.NET Assembly

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 1.1, 2.0, 3.5, 4.0, 4.5 and .Net Compact Framework 2.0, 3.5.

File .NET Framework Version
EASendMail.dll Built with .NET Framework 1.1
It requires .NET Framework 1.1, 2.0, 3.5 or later version.
EASendMail20.dll Built with .NET Framework 2.0
It requires .NET Framework 2.0, 3.5 or later version.
EASendMail35.dll Built with .NET Framework 3.5
It requires .NET Framework 3.5 or later version.
EASendMaill40.dll Built with .NET Framework 4.0
It requires .NET Framework 4.0 or later version.
EASendMaill45.dll Built with .NET Framework 4.5
It requires .NET Framework 4.5 or later version.
EASendMailCF20.dll Built with .NET Compact Framework 2.0
It requires .NET Compact Framework 2.0, 3.5 or later version.
EASendMailCF35.dll Built with .NET Compact Framework 3.5
It requires .NET Compact Framework 3.5 or later version.

VB.NET - Send Email over TLS on 25 or 587 Port - Example

The following example codes demonstrate how to send email over TLS connection on 25 or 587 port. 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.

' Add EASendMail namespace
Imports EASendMail

Module Module1
    Sub Main()
        Dim oMail As New SmtpMail("TryIt")
        Dim oSmtp As New SmtpClient()

        ' 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 email from VB.NET project over TLS 25"

        ' Set email body
        oMail.TextBody = "this is a test email sent from VB.NET project, do not reply"

        ' Your SMTP server address
        Dim oServer As 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"

        ' Set 25 or 587 SMTP Port
        oServer.Port = 25

        ' Detect TLS connection automatically
        oServer.ConnectType = SmtpConnectType.ConnectSSLAuto


        Try

            Console.WriteLine("start to send email ...")
            oSmtp.SendMail(oServer, oMail)
            Console.WriteLine("email was sent successfully!")

        Catch ep As Exception

            Console.WriteLine("failed to send email with the following error:")
            Console.WriteLine(ep.Message)
        End Try

    End Sub
End Module

Appendix

Comments

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