If you are having trouble submitting or receiving e-mail, and you believe that the anti-relay provisions might be causing the problem, please read the checklist below.

• You are using a POP mailer (such as Eudora), connecting from home through an ISP.
  • (a) You find you can no longer submit outgoing mail to one of our machines. This is to be expected. Anyone not in the .concordia.ca domain should submit outbound e-mail through their ISP's SMTP relay. This "problem" can appear in one of appear in one of two ways:
    • You are trying to send your message by connecting to one of our "trusted mailers": see "551 Relaying denied" below.
    • You are trying to send your message by connecting to any other Concordia machine's mail port. You connection simply times out.

    In either case, the remedy is to use your ISP's mail relay machine to submit your outgoing mail (but you can still read your Concordia mail as usual).

  • (b) You are having some other kind of e-mail problem, and you wonder if the new antispam stuff is causing it. In all cases, a copy of the error message is needed to debug the problem. The antispam stuff may produce any of the following messages:
    • 451 invalid sender hostname

      This means that the "envelope sender" had a hostname that we could not resolve in the DNS. When this happens, it is usually a spam attempt (e.g. "CALL-NOW@1-800-555-1212"). (You're not trying to spam, are you?)

      Occasionally it's someone munging their hostname on purpose (e.g. "anne@alcor-no-spam.concordia.ca"), or a typo in a client configuration (e.g. "anne@aclor.concordia.ca"). Check and fix your client (Eudora) configuration. Your "pop account" should have your fully qualified domain name (e.g. "anne@alcor.concordia.ca").

    • 550 sender domain name required

      This means that the "envelope sender" had a username but no hostname (e.g. just "anne"); this is usually caused by a misconfigured client. Check and fix your client (Eudora) configuration; your "pop account" should have your fully qualified domain name (e.g. "anne@alcor.concordia.ca").

    • 551 Relaying denied

      This is because you, on an offsite machine (i.e. one not in .concordia.ca), are trying to submit mail for an address not at Concordia. We don't allow this any more, because it is a favourite tactic of spammers. In order to be able to submit your message, you must use your ISP's mail relay machine to submit your outgoing mail.

      Also, please note that some departments at Concordia restrict relaying to their own subdomain, so you may not be allowed to submit your message through those hosts even if you are trying to submit mail from an address within Concordia.

    More information is available about Concordia's anti-spam measures.

  In all cases, if we can't see the error, we can't help with the problem. If someone says that mail to you from offsite is disappearing down a black hole with no error messages, then it has to be traced from the other end. The sender should get help from their postmaster, who should be able to determine where the mail stops. The foreign postmaster can then contact if s/he believes there is a problem at our end.

  If you get really stuck, remember you can always post to the help newsgroup, concordia.dept.iits.help.

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  Copyright, © 2003, Concordia University, Instructional and Information Technology Services (IITS). Author: Anne Bennett Credits: (none) Maintained by: postmaster@concordia.ca Last update: 1998/09/10 -- Dana Echtner