Visual Basic 6.0

IMAP SSH Tunneling (Port Forwarding)

Demonstrates how to setup and use an SSH tunnel for IMAP. Visual Basic 6.0

Dim success As Long
success = 0

' This example assumes the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

Dim imap As New ChilkatImap

' The SSH hostname may be a hostname or an 
' IP address, such as "192.168.1.108".
' The port is typically 22 (the standard port for SSH).
Dim sshHostname As String
sshHostname = "www.mysshserver.com"
Dim sshPort As Long
sshPort = 22

' Connect to an SSH server and establish the SSH tunnel:
success = imap.SshOpenTunnel(sshHostname,sshPort)
If (success = 0) Then
    Debug.Print imap.LastErrorText
    Exit Sub
End If

' Authenticate with the SSH server via a login/password
' or with a public key.
' This example demonstrates SSH password authentication.
' Note: This is not authenticating with the IMAP server, it is
' for authenticating with the SSH server, which is separate.
success = imap.SshAuthenticatePw("mySshLogin","mySshPassword")
If (success = 0) Then
    Debug.Print imap.LastErrorText
    Exit Sub
End If

' OK, the SSH tunnel is setup.  The IMAP component may
' be used exactly the same as usual, except all communications
' are sent through the SSH tunnel.

' Connect to an IMAP server via the SSH tunnel.
' Because the SSH tunnel has been previously setup,
' this does not establish a direct connection with the IMAP
' server.  It directs the SSH server to establish the connection.

' In this example, the IMAP server requires SSL/TLS.  The TLS connection
' will be enclosed within the SSH tunnel.
imap.Ssl = 1
imap.Port = 993
success = imap.Connect("imap.my-imap-server.com")
If (success = 0) Then
    Debug.Print imap.LastErrorText
    Exit Sub
End If

' Authenticate with the IMAP server via the SSH tunnel.
success = imap.Login("myLogin","myPassword")
If (success = 0) Then
    Debug.Print imap.LastErrorText
    Exit Sub
End If

' Select an IMAP mailbox
success = imap.SelectMailbox("Inbox")
If (success = 0) Then
    Debug.Print imap.LastErrorText
    Exit Sub
End If

' How many messages in Inbox?
Dim msgCount As Long
msgCount = imap.NumMessages
If (msgCount = 0) Then
    Debug.Print "No messages found."
    Exit Sub
End If

Dim upperBound As Long
upperBound = 10
If (msgCount < upperBound) Then
    upperBound = msgCount
End If

' Download up to the 1st 10 messages.
Dim email As New ChilkatEmail
Dim i As Long
Dim bUid As Long
bUid = 0
For i = 1 To upperBound

    success = imap.FetchEmail(0,i,bUid,email)
    If (success = 0) Then
        Debug.Print imap.LastErrorText
        Exit Sub
    End If

    Debug.Print email.From
    Debug.Print email.Subject
    Debug.Print "----"
Next

' Disconnect from the IMAP server.
' The SSH tunnel remains open.
success = imap.Disconnect()
If (success = 0) Then
    Debug.Print imap.LastErrorText
    Exit Sub
End If

' It is possible to re-use the existing SSH tunnel for the next connection:
success = imap.Connect("imap.my-imap-server2.com")
If (success = 0) Then
    Debug.Print imap.LastErrorText
    Exit Sub
End If

' Review the LastErrorText to see that the connection was made via the SSH tunnel:
Debug.Print imap.LastErrorText

success = imap.Disconnect()
If (success = 0) Then
    Debug.Print imap.LastErrorText
    Exit Sub
End If

' Finally, close the SSH tunnel.
success = imap.SshCloseTunnel()
If (success = 0) Then
    Debug.Print imap.LastErrorText
    Exit Sub
End If

Debug.Print "IMAP SSH tunneling example completed."