If you are a Business Manger or Administrator planning to buy an anti spam product soon, below is a list of features that a product must have, make sure you check this before you make a decision to buy their product: -

• E-mail Header Analysis and checking
• Real Time DNS Blacklist (DNSBL) Checking
• Greylisting
• Anti Directory Harvesting (Active Directory and LDAP Support)
• Content Scanning (Bayesian Analysis)
• Reputation Checks
• Features for users to add email address to Black list or White list.
• Reports

Above listed are some core features that must be in an anti spam product. If you think I missed some important features please do let me know. In coming weeks I will discuss individual features separately. As I always mention in my blog post, If you've got ideas, suggestions, questions or other ways to control spam please let me know, by leaving a comment here.