VB.NET - Retrieve Email from Gmail Account

The following vb.net example codes demonstrate how to retrieve email from Gmail IMAP4 server.

Gmail POP3 and IMAP4 Setting

Gmail POP3 server address is pop.gmail.com. It requires SSL connection on 995 port, and you should use your Gmail email address as the user name for user authentication.

Gmail IMAP4 server address is imap.gmail.com. It requires SSL connection on 993 port, and you should use your Gmail email address as the user name for user authentication. For example: your email is gmailid@gmail.com, and then the user name should be gmailid@gmail.com.

To retrieve email from Gmail account, you need to enable POP3 or IMAP4 access in your gmail account settings.

Because Gmail POP3 server doesn’t work like normal POP3 server, it hides old emails automatically even the email was not deleted, so we suggest that you use IMAP4 protocol.

Server Port SSL Protocol
pop.gmail.com 995 SSL required Pop3
imap.gmail.com 993 SSL required Imap4 (recommended)

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 IMAP OAUTH section.

Installation

Before you can use the following sample codes, you should download the EAGetMail Installer and install it on your machine at first. Full sample projects 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 EAGetMail

Note

If you install it by NuGet, no sample projects are installed, only .NET assembly is installed.

Add Reference

To use EAGetMail POP3 & IMAP Component in your project, the first step is “Add reference of EAGetMail to your project”. Please create or open your project with Visual Studio, then go to menu -> Project -> Add Reference -> .NET -> Browse..., and select EAGetMail{version}.dll from installation path, click Open-> OK, the reference will be added to the project, you can start to use it to retrieve email and parse email in your project.

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

.NET Assembly

Because EAGetMail 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
EAGetMail.dll Built with .NET Framework 1.1
It requires .NET Framework 1.1, 2.0, 3.5 or later version.
EAGetMail20.dll Built with .NET Framework 2.0
It requires .NET Framework 2.0, 3.5 or later version.
EAGetMail35.dll Built with .NET Framework 3.5
It requires .NET Framework 3.5 or later version.
EAGetMail40.dll Built with .NET Framework 4.0
It requires .NET Framework 4.0 or later version.
EAGetMail45.dll Built with .NET Framework 4.5
It requires .NET Framework 4.5 or later version.
EAGetMailCF20.dll Built with .NET Compact Framework 2.0
It requires .NET Compact Framework 2.0, 3.5 or later version.
EAGetMailCF35.dll Built with .NET Compact Framework 3.5
It requires .NET Compact Framework 3.5 or later version.

VB.NET - Retrieve Email from Gmail Account - Example

The following example codes demonstrate how to use EAGetMail POP3 component to download email from Gmail IMAP server. In order to run it correctly, please change email server, user, password, folder, file name value to yours.

Note

To get full sample projects, please download and install EAGetMail on your machine.

Because Gmail POP3 server doesn’t work like normal POP3 server, it hides old emails automatically even the email was not deleted, so we suggest that you use IMAP4 protocol.

Imports System.IO

' Imports EAGetMail namespace
Imports EAGetMail

Module Module1
    Sub Main()
        ' Create a folder named "inbox" under current directory
        ' to save the email retrieved.
        Dim curpath As String = Directory.GetCurrentDirectory()
        Dim mailbox As String = [String].Format("{0}\inbox", curpath)

        ' If the folder is not existed, create it.
        If Not Directory.Exists(mailbox) Then
            Directory.CreateDirectory(mailbox)
        End If

        ' Gmail IMAP server is "imap.gmail.com"
        Dim oServer As New MailServer("imap.gmail.com", _
            "gmailid@gmail.com", "yourpassword", ServerProtocol.Imap4)
        Dim oClient As New MailClient("TryIt")

        ' Enable SSL connection
        oServer.SSLConnection = True

        ' Set IMAP4 SSL port
        oServer.Port = 993

        Try
            oClient.Connect(oServer)
            Dim infos As MailInfo() = oClient.GetMailInfos()
            For i As Integer = 0 To infos.Length - 1
                Dim info As MailInfo = infos(i)
                Console.WriteLine("Index: {0}; Size: {1}; UIDL: {2}", _
                        info.Index, info.Size, info.UIDL)

                ' Receive email from Gmail server
                Dim oMail As Mail = oClient.GetMail(info)

                Console.WriteLine("From: {0}", oMail.From.ToString())
                Console.WriteLine("Subject: {0}" & vbCr & vbLf, oMail.Subject)

                ' Generate an email file name based on date time.
                Dim d As System.DateTime = System.DateTime.Now
                Dim cur As New System.Globalization.CultureInfo("en-US")
                Dim sdate As String = d.ToString("yyyyMMddHHmmss", cur)
                Dim fileName As String = [String].Format("{0}\{1}{2}{3}.eml", _
                    mailbox, sdate, d.Millisecond.ToString("d3"), i)

                ' Save email to local disk
                oMail.SaveAs(fileName, True)

                ' Mark email as deleted in Gmail Account
                oClient.Delete(info)
            Next

            ' Quit and purge emails marked as deleted from Gmail IMAP4 server.
            oClient.Quit()
        Catch ep As Exception
            Console.WriteLine(ep.Message)
        End Try

    End Sub
End Module

Gmail IMAP 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 IMAP OAUTH

Appendix

Comments

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