NAU to implement e-mail sender quotas

Northern Arizona University will re-implement e-mail sender quotas beginning Dec 8 to aid in the ongoing battle against spam.

These quotas involve sending e-mail only and have nothing to do with quotas on individual boxes or e-mail stored in individual accounts. The quotas were enforced in the past but there was a hiatus as the Iris Exchange e-mail system was implemented.

The quotas will protect NAU’s e-mail reputation and prevent other e-mail providers from denying service to NAU. Occasionally, an NAU e-mail account becomes compromised following a phishing incident or a computer becomes infected with a virus or other malware and is covertly sending out spam in the background. The quotas are designed to help ITS identify and rectify those situations as they arise, as well as to prevent NAU from spamming others.

In order to balance legitimate work needs against the volume normally sent by infected systems, the default quota of messages to addresses outside of NAU is 600 messages per hour. Sending more than that—intentionally or not—would result in receiving an error message or the e-mail program will retry again later. If a user receives an error and has not intentionally sent a large volume of e-mails, that would be an indication to contact ITS.


  • Messages sent by the list server ( are not counted.
  • Messages sent from an NAU Iris Exchange address to another NAU Iris Exchange address
    ( will not be counted.

Much larger quotas are available in the “trusted/whitelisted” group (addresses that deal with very large campus notifications or business) and “big sender” group (departments that send large amounts of mail). Where known, those larger quotas will already be assigned. However, if you have any questions about this resumption, or would like to verify or request a larger quota, contact the Solution Center at (928) 523-1511 or