CoSE IT manages several mailing lists that are hosted through ISU
These lists use a technique called greylisting to reduce spam. It keeps track of a three pieces of information about each mail, sending IP address, sender email, recipient email. The first time the server encounters a new combination, it delays delivery for 1 hour. It denies the request the first time, but correctly configured email servers retry in an hour and the server has now seen this combination before, and accepts the mail. Many spambots are not correctly configured email servers, and don't retry. What it means to you the first time you send an email to a new list, or from a new IP (home IP's are sometimes dynamic, and may change each time) your mail may be delayed one hour. Subsequent mail sent from the same IP to the same recipient (in this case the mailing list) is not delayed.
If you need to add or remove people from a mailing list, please fill out the following form for documentation purposes, and we'll get back to you as soon as possible: