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Open Relaying Background

This page provides background information on open relaying is and why it is a problem.

When a person dials into service X and uses service Y's SMTP (outgoing) mail server to send mail (generally, though not always, to one or more people who are unrelated to either service), the result is called relaying.

Contents

• You have a relaying problem if you ...
• Why would a university want to provide this capability?
• What's the problem with open relaying?
• The Solution

Occurrence of Open Relay Problem

• Dial in to an ISP (Internet Service Provider) - other than the University of Maryland.
• Use a machine on a network - other than the University of Maryland.
• You can receive email, but you can no longer send email to non-University of Maryland email addresses. You may receive an error message including the phrase, "Relaying Denied." Or, your mail bounces, giving the reason:

  ----- Transcript of session follows ----- .. while talking to . . . . >>> 550 relaying denied

  
  

Page Has Been Retired

• University faculty go on sabbatical all over the world.
• University students go home for holidays.
• Both groups often wish to avoid the time quotas that heavy use of the University dialups has made necessary.
• They all want to send and receive mail using their University email accounts.

The most reliable method for doing so is for them to use the mail servers dedicated to those email accounts. However, when they are off campus, they get their Internet access through an institution or Internet Service Provider (ISP) which is not part of the University. In order to make it possible for its far-flung members to use its mail servers without possible limitations imposed by these non-UM service providers, the University has configured its mail servers to permit relaying -- i.e., to be used by people who are not dialed into (or directly on) the University network.

Problem with Open Relaying

The issue of relaying creating problems has been around for a long time. spammers (people who send unwanted email) frequently use it to hide who they are or where their mail is coming from.

Picture the following:

• ISP #1 has an SMTP server with an open relay.
• spammers use it to send mail to ISP #2.
• ISP 2's users complain, either to ISP 1 directly or through their own ISP 2.
• ISP 2 decides to avoid such hassles by blocking all mail passing through ISP 1.
• ISP 1's customers then complaint to ISP 1 about being unable to send mail to ISP 2 users.
• ISP 1 ends up being forced to close down the open relay.

ISP 1 is the University, and ISP 2 is a service for someone you want to send mail to. You get the picture.

Solution to Open Relay

• The best solution to this problem is to use the SMTP server associated with the ISP or network you are using. This simply means putting the address of that SMTP server into your e-mail software, in the "Outgoing Mail Server" or "SMTP Server" box.

  In most cases, you can do this while still using your UMCP email address as your return address. For your convenience, we have compiled a list of some SMTP server names for various ISP's that will permit this.

  AOL users note - Unfortunately, this approach will not work with AOL, because AOL does not provide an SMTP server for its customers.

• If the solution described above won't work for you, other possibilities (not necessarily the most convenient or most secure) include:
  • Download and install our Virtual Private Network client software. Use of this client will allow a connection through any ISP world-wide seem to be coming directly into the University of Maryland network. This allows use of the University's SMTP servers and access to restricted sites such as libraries and databases.
  • Web-based e-mail programs - Many of these services (e.g., www.homemail.com, www.readmail.com) will allow you to read your mail (often with very poor security), but not to send it. Others are full service (e.g., www.hotmail.com, www.yahoo.com), but you can't identify yourself by your University of Maryland email address.
  • The following is what we have been able to locate in terms of a service that will permit you to both read and send mail. We aren't recommending this approach, nor can we provide technical support for this approach, because of issues of:
    • Security: sending your id/password unencrypted over the Internet -- and if you choose to read your email on the site, make sure to use the IMAP approach, so that your mail stays on the server instead of being downloaded.
    • Privacy: gathering demographic information and sharing it with advertisers to which you are subject on the site, and about whom you will receive email if you fail to opt out at the right moment.