Why is there so much spam?

As you have no doubt noted, we are getting more spam than ever before and the spam problem seems to have gotten much worse within the last three weeks. The reason for this is that the spammers have had a lot of success recently in using "bots" to send their spam. A bot is a regular user's computer that has been taken over by the spammer and is being used to send spam, often without the knowledge of the computer's user (this is a good reason to keep your anti-virus software up to date).

Currently we have two types of filtering in place. We block emails from known spammers via a Realtime Blackhole List and we have content based filtering available. As of November 17th, 2006 we will be adding a new type of filtering called greylisting to every account on CityNet. We have been running greylisting on our own accounts for the last few weeks and we are VERY happy with the results. We think you will be too. Please read on for the details though as greylisting will cause some email to be delayed.

How it works:

Any email message sent to you on the first attempt will be rejected by CityNet's server with a temporary failure. The sending mail server will see that the message has been temporarily rejected and will try to resend the message, usually in about 30-60 minutes. Our server will make the sending server wait 30 minutes prior to accepting the email. After this wait period, your message is accepted and then added to a list of accepted senders and it will automatically be accepted for the next 72 hours. After the 72 hours, the server must again go through through the process of being accepted which insures that our list is always being updated. When spammers get a temporary failure, they usually don't retry the message, so they'll rarely get added to the list of accepted servers.

What you should know: