Retrieve Email over SSL connection in VB.NET¶

In previous section, I introduced how to retrieve email from Exchange Server with WebDAV protocol. In this section, I will introduce how to retrieve email over SSL connection in VB.NET.

Sections:

SSL and TLS
TLS 1.2
[VB.NET Example - SSL/TLS]
[VB.NET Example - Retrieve email from POP3 server over SSL on 995 port]
[VB.NET Example - Retrieve email from IMAP4 server over SSL on 993 port]

SSL and TLS¶

SSL connection encrypts data between the email component and POP3 server or IMAP4 server to protect user, password and email content in TCP/IP level. Now this technology is commonly used and many email servers are deployed with SSL such as Gmail, Yahoo and Hotmail.

There are two ways to deploy SSL on email server:

Implicit SSL

Deploying SSL on another port (POP3: 995 port or IMAP4: 993 port) directly. This is most common way.
Explicit SSL (TLS)

Using STARTTLS or STLS command to switch SSL channel on normal port (POP3: 110 port or IMAP4: 143 port);

TLS 1.2¶

TLS is the successor of SSL, EAGetMail supports SSL 3.0/TLS1.0 - 1.2 very well. In EAGetMail, ConnectTLS doesn’t mean TLS encryption, it means TLS command in POP3/IMAP protocol.

You don’t have to set any property to enable TLS 1.2 encryption. If your server requires TLS 1.2 encryption, TLS 1.2 encryption is used automatically with ConnectTLS, ConnectSSL or ConnectSSLAuto.

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

EAGetMail POP3 component supports both Implicit SSL and Explicit SSL.

For Exchange Web Service/WebDAV protocol, the SSL is based on HTTPS connection, so you just need to set SSLConnection property and simply ignore Port property. Notice: Exchange Web Service requires SSL connection by default.

[VB.NET Example - SSL/TLS]¶

' Retrieve email by normal TCP/IP without SSL connection
' POP3
Dim oServer As New MailServer("myserveraddress", "myuser", "mypassword", _
    False, ServerAuthType.AuthLogin, ServerProtocol.Pop3)

' IMAP4
Dim oServer As New MailServer("myserveraddress", "myuser", "mypassword", _
    False, ServerAuthType.AuthLogin, ServerProtocol.Imap4)

' Retrieve email over SSL connection with direct SSL.
' POP3 SSL
Dim oServer As New MailServer("myserveraddress", "myuser", "mypassword", _
    True, ServerAuthType.AuthLogin, ServerProtocol.Pop3)
oServer.Port = 995

' IMAP4 SSL
Dim oServer As New MailServer("myserveraddress", "myuser", "mypassword", _
    True, ServerAuthType.AuthLogin, ServerProtocol.Imap4)
oServer.Port = 993

' Retrieve email by SSL connection with STARTTLS or TLS command switching
' POP3 TLS
Dim oServer As New MailServer("myserveraddress", "myuser", "mypassword", _
    True, ServerAuthType.AuthLogin, ServerProtocol.Pop3)
oServer.Port = 110
oServer.SSLType = SSLConnectType.ConnectTLS

' IMAP4 STARTTLS
Dim oServer As New MailServer("myserveraddress", "myuser", "mypassword", _
    True, ServerAuthType.AuthLogin, ServerProtocol.Imap4)
oServer.Port = 143
oServer.SSLType = SSLConnectType.ConnectTLS


' Exchange WebDAV
Dim oServer As New MailServer("myserveraddress", _
    "myuser", "mypassword", False,  _
    ServerAuthType.AuthLogin, ServerProtocol.ExchangeWebDAV)

' Exchange Web Service SSL
Dim oServer As New MailServer("myserveraddress", _
    "myuser", "mypassword", True, _
    ServerAuthType.AuthLogin, ServerProtocol.ExchangeEWS)

' Exchange WebDAV SSL
Dim oServer As New MailServer("myserveraddress", _
    "myuser", "mypassword", True, _
    ServerAuthType.AuthLogin, ServerProtocol.ExchangeWebDAV)

Note

Remarks: All of examples in this section are based on first section: 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 to your project.

[VB.NET Example - Retrieve email from POP3 server over SSL on 995 port]¶

The following example codes demonstrate how to retrieve emails from POP3 server over SSL connection on 995 port. In order to run it correctly, please change email server, user, password, folder, file name values.

Note

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

Imports System.Globalization
Imports System.Text
Imports System.IO
Imports EAGetMail 'imports EAGetMail namespace

Module Module1

    Function _generateFileName(ByVal sequence As Integer) As String
        Dim currentDateTime As DateTime = DateTime.Now
        Return String.Format("{0}-{1:000}-{2:000}.eml",
                            currentDateTime.ToString("yyyyMMddHHmmss", New CultureInfo("en-US")),
                            currentDateTime.Millisecond,
                            sequence)
    End Function

    Sub Main()

        Try
            ' Create a folder named "inbox" under current directory
            ' to save the email retrieved.
            Dim localInbox As String = String.Format("{0}\inbox", Directory.GetCurrentDirectory())

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

            Dim oServer As New MailServer("pop3.emailarchitect.net",
                        "test@emailarchitect.net",
                        "testpassword",
                        ServerProtocol.Pop3)

            ' Enable SSL/TLS connection, most modern email server require SSL/TLS connection by default.
            oServer.SSLConnection = True
            ' Set 995 POP3 SSL PORT
            oServer.Port = 995

            Console.WriteLine("Connecting server ...")

            Dim oClient As New MailClient("TryIt")
            oClient.Connect(oServer)

            Dim infos As MailInfo() = oClient.GetMailInfos()
            Console.WriteLine("Total {0} email(s)", infos.Length)

            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)

                ' Retrieve email from POP3 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 unqiue email file name based on date time.
                Dim fileName As String = _generateFileName(i + 1)
                Dim fullPath As String = String.Format("{0}\{1}", localInbox, fileName)

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

                ' Mark email as deleted from POP3 server.
                oClient.Delete(info)

            Next

            ' Quit and expunge emails marked as deleted from POP3 server.
            oClient.Quit()
            Console.WriteLine("Completed!")

        Catch ep As Exception
            Console.WriteLine(ep.Message)
        End Try

    End Sub
End Module

[VB.NET Example - Retrieve email from IMAP4 server over SSL on 993 port]¶

The following example codes demonstrate how to retrieve emails from IMAP4 server over SSL connection on 993 port. In order to run it correctly, please change email server, user, password, folder, file name values.

Note

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

Imports System.Globalization
Imports System.Text
Imports System.IO
Imports EAGetMail 'imports EAGetMail namespace

Module Module1

    Function _generateFileName(ByVal sequence As Integer) As String
        Dim currentDateTime As DateTime = DateTime.Now
        Return String.Format("{0}-{1:000}-{2:000}.eml",
                            currentDateTime.ToString("yyyyMMddHHmmss", New CultureInfo("en-US")),
                            currentDateTime.Millisecond,
                            sequence)
    End Function

    Sub Main()

        Try
            ' Create a folder named "inbox" under current directory
            ' to save the email retrieved.
            Dim localInbox As String = String.Format("{0}\inbox", Directory.GetCurrentDirectory())

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

            Dim oServer As New MailServer("imap.emailarchitect.net",
                        "test@emailarchitect.net",
                        "testpassword",
                        ServerProtocol.Imap4)

            ' Enable SSL/TLS connection, most modern email server require SSL/TLS connection by default.
            oServer.SSLConnection = True
            ' Set 993 IMAP SSL Port
            oServer.Port = 993

            Console.WriteLine("Connecting server ...")

            Dim oClient As New MailClient("TryIt")
            oClient.Connect(oServer)

            Dim infos As MailInfo() = oClient.GetMailInfos()
            Console.WriteLine("Total {0} email(s)", infos.Length)

            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)

                ' Retrieve email from IMAP 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 unqiue email file name based on date time.
                Dim fileName As String = _generateFileName(i + 1)
                Dim fullPath As String = String.Format("{0}\{1}", localInbox, fileName)

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

                ' Mark email as deleted from IMAP server.
                oClient.Delete(info)

            Next

            ' Quit and expunge emails marked as deleted from IMAP server.
            oClient.Quit()
            Console.WriteLine("Completed!")

        Catch ep As Exception
            Console.WriteLine(ep.Message)
        End Try

    End Sub
End Module

Next Section

At next section I will introduce how to download emails from Gmail account.

Tutorial Index

Retrieve Email over SSL connection in VB.NET¶

SSL and TLS¶

TLS 1.2¶

[VB.NET Example - SSL/TLS]¶

[VB.NET Example - Retrieve email from POP3 server over SSL on 995 port]¶

[VB.NET Example - Retrieve email from IMAP4 server over SSL on 993 port]¶

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