Re: antivirus & antispam software

How is the software going to decide which download or mail is supposed to be Spam or contain a virus ?

For virus detection I suppose you need to use a (payed) service that updates the pattern file and the detection software on a regular basis.

I don't know if something like this exists for Spam detection. Otherwise you need to use a channel from the users to the router to have them define rules for Spam detection. Thunderbird is an open source project that does a fairly nice Spam detection based on automatically generated rules. Maybe you can look at it's code.

A primary Spam filter mechanism is to start to send a mail to the sender of any mail and abort after the verification of the addressee. If the verification of the sender fails, the mail can be considered to be Spam.