At a Glance
 
Central Software
CityVoD - CSC Forum Archive
Software List on CSC Student LAN

Location and Floor Plan of the CSC Teaching Studio Areas
Opening Hours of the CSC
Systems Maintenance Schedule
List of Blocked Network Cards / IP Addresses
List of CSC Representatives
List of Departmental Network Administrators
Staff Computer Courses
Sitemap
 
CSC e-Forms
 
Submit CSC Work Req.
Req. for Printing
Req. for Dump / Restore
Teaching Studio Booking / Cancellation
Email Alias Application
Apply for a New Domain Name
Remove an Existing Domain Name
Modify the Hosting of an Existing Domain Name
 
Useful Links
 
OCIO Home
IT Information for Students
IT Information for Staff
IT Information for Alumni
 
Got any questions, comments or suggestions? Contact the editors at ccnetcom@cityu.edu.hk
Issue 51 - March 2007
Current Email Spam and Anti-spam Situation on Campus
By Henry Wong

It is a known fact that Email Spam (or Junk Email) cause annoyance and pose security threats to our users. What is not trivial and yet has significant impact to users is that these spam emails use up a lot of system resources and affect the quality of the Email services. Since last fall, the amount of total emails received from outside has sharply increased to a level that our Email services were seriously affected. According to the statistics generated by the spam-detection software, at least 50% of those emails were almost certain to be spam. A lot of system resources were thus wasted on processing those spam emails and the delivery of normal email was often delayed by hours!

It is necessary to curb the problem by adopting the appropriate method to handle email spam without affecting the users too much. Thus, the Committee on Information System and Technology (CIST), at its last meeting in December 2006, unanimously agreed to adopt the "drop method" approach to remedy the situation. Under this approach, those email messages that are tagged by the reliable spam detection software with a "spam level" score equals to 99% or above (that means they are almost certain to be spam) will be automatically dropped at the incoming email gateway.

The adopted approach has been implemented since 8 January 2007. Together with other email system enhancements (Ref: Network Computing Issue 50 - December 2006), the following benefits have been achieved:

  • Reduce the delay of email delivery and the chance of email congestion. Especially, the average delay of delivering internal email has reduced from 30 minutes on average to less than ONE minute!
  • Reduce complaints from external parties regarding the bouncing of undeliverable spam email messages.
  • Save significant system resources from delivering several tens of thousands of junk email messages everyday.
  • Save storage space (both system and user mailbox spaces) from storing the junk email messages. Those junk emails, if not dropped, will occupy several hundreds of Mbytes of storage space everyday.

The Computing Services Centre (CSC) will regularly review the situation of spam handling process and the email server performance in order to ensure the quality of the email services.

Also in this issue...
Latest Developments on the e-Learning Project
Broadband Internet Access at Wi-Fi Hotspots
Windows Vista at CityU
Fast Printing Service Support to Better Serve the Campus Community



 

Current & Back Issues
 
 
Search Articles
 
 
FAQs
 
Microsoft Windows10
Microsoft Windows 7
Office 365 ProPlus
Microsoft Office 2013
Microsoft Office 2010
中文支援常見問題
Internet Explorer 11
Internet Explorer 9
Email Services
Confidential Email
Wireless LAN
Virtual Desktop Service (VDS)
USB Flash Drive
Mirroring360
CityU SMS (for Department)
CityU SMS (for Staff & Student)
iPad (iOS 5.x)
Wiping a Mobile Device
Wiping Mass Storage Device
Handling Handheld Smart Devices for Service Maintenance, Recycling Use, and Disposal
Staff Account Renewal
Changing Local Administrator Password
McAfee Endpoint Security
Full Scan of Your Computer for Concealed Computer Virus
Anti-spyware
Computer Warranty Scheme Software Copyright Declaration and Compliance Observation
 
Technical Guides
 
AV Facilities User Guide
Connecting to Wireless LAN (WiFi)
VPN Connection Setup Guide BitLocker To Go User Guide
 
Copyright© Computing Services Centre, City University of Hong Kong. Best viewed in 1024x768 with IE. Javascript enabled. Last modified on Friday December 28 2018 .