SMTP SSH Tunneling (Port Forwarding)

Demonstrates how to setup an SSH tunnel for SMTP. This example connects to an SMTP sever via an SSH tunnel and sends an email.

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LOCAL loMailman
LOCAL lnSuccess
LOCAL lcSshHostname
LOCAL lnSshPort
LOCAL lnBSmtp
LOCAL loEmail

*  The mailman object is used for sending (SMTP) and receiving (POP3) email.
loMailman = CreateObject('Chilkat.MailMan2')

*  Any string argument automatically begins the 30-day trial.

lnSuccess = loMailman.UnlockComponent("30-day trial.")
IF (lnSuccess <> 1) THEN
    =MESSAGEBOX("Component unlock failed")
    QUIT
ENDIF

*  Connect to an SSH server and establish the SSH tunnel:

*  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).
lcSshHostname = "www.my-ssh-server.com"
lnSshPort = 22
lnBSmtp = 1
*  The 1st argument passed to SshTunnel indicates whether
*  a tunnel for SMTP or POP3 is being established.
lnSuccess = loMailman.SshTunnel(lnBSmtp,lcSshHostname,lnSshPort)
IF (lnSuccess <> 1) THEN
    =MESSAGEBOX(loMailman.LastErrorText)
    QUIT
ENDIF

*  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 SMTP server, it is
*  for authenticating with the SSH server, which is separate.
lnSuccess = loMailman.SshAuthenticatePw(lnBSmtp,"sshLogin","sshPassword")
IF (lnSuccess <> 1) THEN
    =MESSAGEBOX(loMailman.LastErrorText)
    QUIT
ENDIF

*  OK, the SSH tunnel is setup.  The mailman may
*  be used exactly the same as usual, except all communications
*  are now sent through the SSH tunnel.

*  Set the SMTP server.
loMailman.SmtpHost = "smtp.chilkatsoft.com"

*  Set the SMTP login/password (if required)
loMailman.SmtpUsername = "smtpLogin"
loMailman.SmtpPassword = "smtpPassword"

*  Create a new email object
loEmail = CreateObject('Chilkat.Email2')

loEmail.Subject = "This is a test"
loEmail.Body = "This is a test"
loEmail.From = "Chilkat Support <support@chilkatsoft.com>"
loEmail.AddTo("Chilkat Admin","admin@chilkatsoft.com")

*  The call to SendEmail automatically connects to the SMTP
*  server via the SSH tunnel (if not already connected).
*  Because the SSH tunnel has been previously setup,
*  this does not establish a direct connection with the SMTP
*  server.  It directs the SSH server to establish the connection.

*  After SendEmail completes, the connection (i.e. session) remains
*  open so that subsequent SendEmail calls may use the
*  same SSH tunnel.
lnSuccess = loMailman.SendEmail(loEmail)
IF (lnSuccess <> 1) THEN
    =MESSAGEBOX(loMailman.LastErrorText)
    QUIT
ENDIF

*  If you're curious, have a look at LastErrorText after
*  a successful send.  You'll see detailed information that
*  confirms the SSH tunneling.
=MESSAGEBOX(loMailman.LastErrorText)

*  Note: Some SMTP servers do not actually send the email until
*  the connection is closed.  In these cases, it is necessary to
*  call CloseSmtpConnection for the mail to be  sent.
*  Most SMTP servers send the email immediately, and it is
*  not required to close the connection.

=MESSAGEBOX("Mail Sent!")