Maintaining Anti-Spam Systems

1. 24 Hours of Exchange Server 2007 (Part 13 of 24): Maintaining Anti-Spam Systems Harold Wong [email_address] blogs.technet.com/haroldwong Audio: please try Streaming Internet Audio first If that doesn’t work, use: (800) 618-7506: Pin 5800

11. Exchange Server 2007 Anti-Spam Functionality Connection filtering Sender filtering Recipient filtering Sender ID filtering Content filtering Sender reputation filtering Attachment filtering Outlook junk e-mail filtering

12. Anti-Spam Mail Flow Connection filtering Sender and recipient filtering Sender ID filtering Content filtering Outlook junk e-mail filtering

13. The Defense-in-Depth Approach Perimeter Firewall Edge Transport Server Interior Firewall Hub Transport Server Mailbox Server Client Access Server Outlook E-mail Filtering

18. Connection Filtering Yes Yes No Yes Yes IP allow list IP block list Safe provider list RBL No No No

19. Sender and Recipient Filtering Delete message Reject via SMTP Yes Yes On sender filter list On recipient block list No No

20. Sender ID Filtering Delete message Filter message No Yes No From blocked domain Allow sender ID failed On blocked sender list Yes No Yes Query SPF on sender’s DNS DNS

21. Content Filtering Delete message Reject via SMTP Send to spam quarantine mailbox Microsoft update No No Yes Yes SCL exceeds deletion SCL exceeds rejection No Apply content filter Assign SCL rating Yes SCL exceeds quarantine Safelist Aggregation

23. Exchange Server Hosted Filtering Illegitimate senders Spam quarantine Directory service Exchange hosted filtering

24. Other Strategies and Techniques Sender reputation filtering Attachment filtering Spam quarantine Outlook junk e-mail filtering