We were getting spammed to death! We hadnt practiced good e-mail address practices in the past and now some users were getting blasted with 20 or more spams a day and over 50 during the weekends. Spam became an issue at management and IT meetings. We had to do something. Many users Inboxes became almost unmanageable. Pressing the Delete key is easy but wading through 20 spams to find two good e-mails is a total waste of time.
Spam became the bane of my existence.
We tried everything at the desktop level using Outlook and Exchange filters, rules and anti-spam add-on programs. They just didnt work well for us. Good mail got rejected and spam still got through.
Luckily for us, our Raptor/Symantec Enterprise firewall supported the use of one Real Time Black Hole List (RBL). The default service was MAPS; however, they wanted money for their service and wouldnt let us test the service first.
Not knowing much about RBLs and after being spoiled by our Apache/Linux web server cost (that is, zero), we decided to pursue other options. Our company is going through a "belt-tightening" process.
We then shifted gears and looked into creating a mail proxy server using Spam Assassin and Linux. Our research for Spam Assassin pointed us in Spamcops direction; Spamcop has a free RBL (bl.spamcop.net).
We configured our firewall to use Spamcop and wham! We started blocking hundreds of spam attempts per day.
Now we were onto something. We started blocking a large majority of our spam using just one RBL and we were rejecting it at the perimeter, so it didnt clog up our mail servers or users folders. Most of the desktop-based programs redirect incoming spam to a folder on the mail server.