Send Email using Gmail in VB.NET

In previous section, I introduced how to send email over SSL/TLS connection. In this section, I will introduce how to send email using Gmail account in VB.NET.

Introduction

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.

For example: your email is gmailid@gmail.com, and then the user name should be gmailid@gmail.com.

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

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.

Note

Remarks: All of samples in this section are based on first section: Send email in a simple VB.NET project. To compile and run the following example codes successfully, please click here to learn how to create the test project and add reference of EASendMail to your project.

[VB.NET - Send Email using Gmail Account over Implicit SSL on 465 Port]

The following example codes demonstrate how to send email using Gmail account over SSL in VB.NET.

Note

To get the full sample projects, please refer to Samples section.

Imports EASendMail 'Add EASendMail namespace

Module Module1

    Sub Main()

        Try
            Dim oMail As New SmtpMail("TryIt")
            ' 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"
            ' 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")

            ' 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"

            ' set 465 port
            oServer.Port = 465

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

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

            Dim oSmtp As New SmtpClient()
            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

[VB.NET - Send Email using Gmail Account over Explicit SSL (TLS) on 25 or 587 Port]

The following example codes demonstrate how to send email using Gmail account over TLS in VB.NET. To get full sample projects, please refer to Samples section.

Imports EASendMail 'Add EASendMail namespace

Module Module1

    Sub Main()

        Try
            Dim oMail As New SmtpMail("TryIt")
            ' 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"
            ' 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")

            ' 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"

            ' set 587 port, if you want to use 25 port, please change 587 to 25
            oServer.Port = 587

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

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

            Dim oSmtp As New SmtpClient()
            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.

Google will disable traditional user authentication in the future, switching to Google OAuth is strongly recommended now.

TLS 1.2

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, and you got connection error with SSL/TLS connection, 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

Next Section

At next section I will introduce how to send email using Yahoo account in VB.

Appendix

Comments

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