Setting Up a Reverse DNS Pointer or Using a Mail Relay (Mail or Site Administrators)

Article: vtkb2821.htm

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Last Updated: Mar 03, 2008

Question:

I have been told that I need to set up a reverse DNS pointer or use a mail relay. What should I do?

Answer:

Important: This article is intended for mail or site administrators.

Your e-mail may be relayed to Virginia Tech via another domain. That domain is being blocked by the VT Mail system. Two possible solutions are:

Configure your Reverse DNS pointer.
Messages may be blocked from being sent to Virginia Tech affiliates because the mail server computer, firewall, or NAT gateway's external IP address resolves to a name that is on Virginia Tech's blocked sites list. Reverse DNS pointers must be configured with the server's Internet Service Provider (ISP). Contact your ISP for more information.
Use your ISP’s Outbound SMTP Relay.
Virginia Tech's mail filtering system will block an e-mail message if the message is relayed to us by any domain listed on the blocked sites list. You may be able to route your e-mail messages through your ISP mail server. To determine if this is possible, contact your ISP. Even though the VT Mail team may block portions of ISPs' networks, they attempt to leave the providers' servers unblocked.

Virginia Tech maintains a list of sites that are blocked from sending e-mail messages to its affiliates. A complete list of sites is available on the Blocked E-mail Sites page (http://www.computing.vt.edu/email_and_calendaring/blockedsites.html). This page is only accessible from a computer on the Virginia Tech network. If you are not connected to the Virginia Tech network or you cannot view the page, contact 4Help by using the Help Request Form (http://4help.vt.edu) or by calling (540) 231-HELP (4357).

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Configure your Reverse DNS pointer.

Use your ISP’s Outbound SMTP Relay.