Do we know any spammers? What do they do? They make a living by minimizing being flagged as spammers.
By spammers, I am not (necessarily) referring to the really nefarious ones.
For example, it is very common practice on commercial websites that are trying to sell a product or service to require your contact information in order to obtain access to free services and information. The welcome email always seems to include the "please add our email address to your white-list". Note that this is done up front before they start spamming me.
--
Gerald