But you can add things to enhance its capabilities.
For example, if you use Thunderbird or Outlook Express and download your
emails to your computer, you also have the capabilities of those programs,
which might (and probably does) allow you to do the kinds of filtering that
meet your specific needs.
Besides, about a third of the spam I get ... and I also get around 300 a day
... comes addressed from ME! It is a common technique the spammers use, to
get past the kind of blocking you want Gmail to do. If it hasn't happened
to you yet, it surely will. If they don't use your address, they will use
common domains like gmail.com, which you probably would include in your
whitelist. So I disagree with you that "there is no reason this cant [sic]
be stopped."
Like I say, I also receive hundreds of spams a day, and with few exceptions
they all land in my Spam box where I can just ignore them.
As an alternative, try this: Add a Filter for every person you want on your
whitelist, and have it Label them as "good" or something similar. Then use
the "good" Label as your inbox. There is a Gmail Labs feature called
"Multiple Inboxes" that lets you substitute it for your regular Inbox.
Voila, Gmail now displays only messages from the people you want. This
doesn't take care of clearing any unwanted spam out of your real Inbox or
All Mail; you would need to check that periodically for anything that didn't
go into the Spam box.
Generally speaking, though, Gmail's built-in spam filtering does an
excellent job of finding spam, once 'trained' (by you) to catch the kind of
spam you tend to receive. Gmail's policy of not automatically deleting
spam, but leaving it for 30 days for you to double-check, is vastly superior
to other email services that blindly delete what they think is spam before
we see it. Which is bound to go wrong.
Andy