B4X

Close the SSH Tunnel

Demonstrates the Chilkat MailMan.SshCloseTunnel method, which closes the SSH tunnel used for SMTP or POP3 communication. This example opens and authenticates a tunnel, performs a mail operation through it, and then closes it.

Background: An SSH tunnel holds an open connection to the SSH server for as long as it is needed, so closing it releases both that connection and the resources on the SSH server. The natural pattern is open → authenticate → do mail work → close. It is the counterpart to SshOpenTunnel, and is separate from closing the mail connections themselves (CloseSmtpConnection / Pop3EndSession), which ride inside the tunnel.

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Dim success As Boolean = False

'  Demonstrates the MailMan.SshCloseTunnel method, which closes the SSH tunnel used for SMTP
'  or POP3 communication.

Dim mailman As ChilkatMailMan
mailman.Initialize("mailman")

'  Configure the POP3 server connection.
mailman.MailHost = "pop.example.com"
mailman.MailPort = 995
mailman.PopSsl = True
mailman.PopUsername = "user@example.com"
mailman.PopPassword = "myPassword"

'  Open and authenticate the SSH tunnel.
success = mailman.SshOpenTunnel("ssh.example.com", 22)
If success = False Then
    Log(mailman.LastErrorText)
    Return
End If


success = mailman.SshAuthenticatePw("sshUser", "sshPassword")
If success = False Then
    Log(mailman.LastErrorText)
    Return
End If


'  ... perform mail operations through the tunnel ...
Dim count As Int = mailman.GetMailboxCount
If count < 0 Then
    Log("Failed to get the mailbox count.")
Else
    Log("Mailbox count: " & count)
End If


'  Close the SSH tunnel when finished with it.
success = mailman.SshCloseTunnel
If success = False Then
    Log(mailman.LastErrorText)
    Return
End If


Log("SSH tunnel closed.")