SpamAssassin settings page.
There's now a place where you can set your SpamAssassin preferences. This includes whitelists and blacklists for allowing/denying specific addresses regardless of whether or not the email is SPAM, and some other options that are described on that page.
Login with your webmail user name and password.
If you've been receiving lots of mail from mailing lists or opt-in lists that are repeatedly and mistakenly marked as SPAM, then you can add those addresses to your whitelist so that they are no longer tagged.

