Problem: Cosine is receiving complaints and observing increased SPAM in Science IMAP accounts at a disproportionate level compared to campus.
Contributing solution: Greylisting
What it is: Greylisting has been used on campus for 5 or 6 years to reduce SPAM. It is a protocol that tells a new or unknown email server (e.g. Google has many different email servers) it is too busy to receive the message. The sending server, if properly configured, queues the message and resends it later (often 15-60 minutes). Once two legitimate message are delivered to two separate email recipients/sender combinations, the new email server is “known” or Whitelisted and future messages sent from that server are no longer delayed.
More information can be found here: https://oregonstate.teamdynamix.com/TDClient/KB/?CategoryID=8893
Why it will help? SPAM email servers don’t queue email and simply discard the message.
Risk or cost to users: Email will be delayed occasionally. The most common delays are 15-60 minutes. Less common, email could be delayed a day. Rarely, if a sending email server is configured incorrectly the message may be lost.
Why don’t we already do it? When greylisting was introduced many messages were delayed or missed as Network Engineering worked out the kinks. In response Cosine opted @science.oregonstate.edu addresses out of the service. While it was the right decision at the time, the greylisting service is better today.
Why now? We believe the increased SPAM to Science IMAP users is not acceptable and this is a proven tool to reduce SPAM. If any Cosine users object to having greylisting on their @science.oregonstate.edu address we can opt individuals out of the service, but we cannot opt users in piecemeal. The vast majority of campus and many users within Cosine (with @oregonstate.edu addresses) are currently using greylising.
Opt out? If you don’t want your email account to be subjected to greylisting we can opt you out of the service selectively. We cannot opt users in, which is why we are opting in the entire Cosine IMAP email server. Please contacthelpdesk@science.oregonstate.edu if you want to opt out after the greylisting change has been made.
