(PowerShell) POP3 over Multiple Hop SSH

Demonstrates how to read POP3 email (using TCP or TLS) tunneled through mulitple-hop SSH. The scheme looks like this:

Application => ServerSSH1 => ServerSSH2 => POP3Server

Chilkat .NET Downloads Chilkat .NET Assemblies

Add-Type -Path "C:\chilkat\ChilkatDotNet47-9.5.0-x64\ChilkatDotNet47.dll"

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

$ssh1 = New-Object Chilkat.Ssh

# Connect directly to the 1st SSH server.
$success = $ssh1.Connect("serverssh1.com",22)
if ($success -ne $true) {
    $($ssh1.LastErrorText)
    exit
}

# Authenticate using login/password:
$success = $ssh1.AuthenticatePw("ssh1Login","ssh1Password")
if ($success -ne $true) {
    $($ssh1.LastErrorText)
    exit
}

# Connect through the 1st SSH connection to reach a 2nd SSH server.
# Note: Any number of SSH connections may be simultaneously tunneled through a single
# existing SSH connection.
$ssh2 = New-Object Chilkat.Ssh
$success = $ssh2.ConnectThroughSsh($ssh1,"serverssh2.com",22)
if ($success -ne $true) {
    $($ssh2.LastErrorText)
    exit
}

# Authenticate with ssh2...
$success = $ssh2.AuthenticatePw("ssh2Login","ssh2Password")
if ($success -ne $true) {
    $($ssh2.LastErrorText)
    exit
}

$mailman = New-Object Chilkat.MailMan

# Tell the mailman object to connect to the POP3 server though the ssh2 tunnel (which itself is routed through ssh1).
# The connection looks like this:  Application => ServerSSH1 => ServerSSH2 => POP3Server
$success = $mailman.UseSsh($ssh2)
if ($success -ne $true) {
    $($mailman.LastErrorText)
    exit
}

# Set the POP3 server's hostname
$mailman.MailHost = "pop.someMailServer.com"

# Set the POP3 login/password.
$mailman.PopUsername = "myLogin"
$mailman.PopPassword = "myPassword"

# Establish the POP3 connection through the ssh2 tunnel.
$success = $mailman.Pop3BeginSession()
if ($success -ne $true) {
    $($mailman.LastErrorText)
    exit
}

# Get the number of messages in the mailbox.
$numMessages = $mailman.GetMailboxCount()

$i = 1

while ($i -le $numMessages) {

    $email = $mailman.FetchByMsgnum($i)
    if ($mailman.LastMethodSuccess -ne $true) {
        $($mailman.LastErrorText)
        exit
    }

    $($email.From + ": " + $email.Subject + "`n")

    $i = $i + 1
}

# Close the connection with the POP3 server.  (This closes the tunnel through ssh2)
# The connection with ssh2 is still alive, and may be used for more connections.
$success = $mailman.Pop3EndSession()

# Close the connection with ssh2.  (This closes the the tunnel through ssh1.)
# The connection with ssh1 is still alive, and may be used for more connections.

$ssh2.Disconnect()

$ssh1.Disconnect()