Using Norton AntiVirus with Port Forwarding Applications

Port forwarding offers a quick and easy way of keeping your personal and company email private and secure. Century Software's TinyTERM Plus includes port forwarding and can be easily configured to work with existing email clients like Microsoft Outlook, Microsoft Outlook Express, and Eudora Pro.

There is a side-effect when using port forwarding to secure email clients: anti-virus software may be bypassed or disabled. This is caused by the way port forwarding works: re-routing the ports monitored by the anti-virus application that are used to send and receive email.

Default mail clients usually use the following ports to send and receive email:

  • Simple Mail Transport Protocol (SMTP) on port 25
  • Post Office Protocol (POP3) on port 110
  • Internet Message Access Protocol (IMAP) on port 143

When an anti-virus program is installed, it "intercepts" communications on these ports to process and scan the incoming and outgoing email for viruses.

When an email client is configured for port forwarding, the ports normally used for SMTP, POP3, and IMAP are changed and re-directed through the port forwarding application for delivery over the encrypted connection. When this happens, the anti-virus software no longer intercepts the communications (because a different set of ports are used), and the email is not scanned for viruses.

Some anti-virus applications use multiple levels of scanning and checking, and can be used in conjunction with port-forwarding applications. The rest of this page describes how to setup Norton AntiVirus to work with port forwarding applications, including Century Software's TinyTERM Plus.

To configure Norton AntiVirus, first launch the application by double-clicking on it's icon in the system tray:

Alternatively, Norton AntiVirus can be launched by clicking on the Start button, then clicking on the Programs button, then clicking on Norton AntiVirus, and then clicking on the application icon.

After the application starts and the splash screen is displayed, you should see the main dialog:

Check to make sure the Auto-Protect icon is not crossed out, and that the text "Auto-Protect is enabled and protecting your system" is displayed. If this is the case, Norton AntiVirus is setup to work with port forwarding.

If the Auto-Protect icon is crossed out and the text "Auto-Protect is disabled and is not protecting your system" is displayed, your email will not be protected when using port-forwarding applications:

To enable Auto-Protect, click on the Enable button. Confirm that the Auto-Protect icon is no longer crossed out and the text reads "Auto-Protect is enabled and protecting your system." Norton AntiVirus is now setup to work with port forwarding applications.

For more information on Auto-Protect and how it works, visit the Symantec website and search for the term "Auto-Protect."