VB.NET - Send Email using Gmail SMTP Server

The following vb.net example codes demonstrate how to send email using Gmail SMTP server.

Gmail SMTP Server

Gmail SMTP server address is smtp.gmail.com. It requires implicit SSL or explicit SSL (TLS) connection, and you should use your Gmail email address as the user name for ESMTP authentication.

Server Port SSL/TLS
smtp.gmail.com 25, 587 TLS
smtp.gmail.com 465 SSL

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 using Gmail SMTP Server - Example

The following example codes demonstrate sending email using Gmail SMTP server. 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.

Important

If you got authentication error, you need to enable Allowing less secure apps or Sign in using App Passwords.

Another way is Gmail OAUH, please see Gmail SMTP OAUTH section.

Imports EASendMail 'Add EASendMail Namespace

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

        ' Your gmail email address
        oMail.From = "gmailid@gmail.com"

        ' Set recipient email address, please change it to yours
        oMail.To = "support@emailarchitect.net"

        ' Set email subject
        oMail.Subject = "test email from gmail account over SSL"

        ' Set email body
        oMail.TextBody = "this is a test email sent from VB.NET project with gmail"

        'Gmail SMTP server address
        Dim oServer As New SmtpServer("smtp.gmail.com")

        ' If you want to use direct SSL 465 or 587 port,
        ' please add this line, otherwise TLS will be used.
        ' oServer.Port = 465

        ' detect SSL/TLS automatically
        oServer.ConnectType = SmtpConnectType.ConnectSSLAuto

        ' Gmail user authentication should use your
        ' Gmail email address as the user name.
        ' For example: your email is "gmailid@gmail.com", then the user should be "gmailid@gmail.com"
        oServer.User = "gmailid"
        oServer.Password = "yourpassword"

        Try

            Console.WriteLine("start to send email over SSL ...")
            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

Gmail SMTP OAUTH

The Gmail IMAP and SMTP servers have been extended to support authorization via the industry-standard OAuth 2.0 protocol. Using OAUTH protocol, user can do authentication by Gmail Web OAuth instead of inputting user and password directly in application. This way is more secure, but a little bit complex.

Using Gmail SMTP OAUTH

Appendix

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