Whitelist

Whitelist:
Whitelist is similar to address book where in we keep the details about the known senders.
Having whitelist in the filter has an advantage that we can accept the mails from the senders in the whitelist without any filtering there by saving computation.
But the problem is that one sender can have different email address. If the known sender has send the mail with his new address and the mail contains words that may increase the probabilty of being considered as spam then there are chances for false positives when passed through the filter.

The whilelist associated with the bayesian solves this problem that as the entire header is checked the senders route, protocol used, the ip address are noted. Thus though the sender uses the different address for the mail the other fields may indicate that the message is from the known person and the mail will be accepted without filtering.