Whitelist

Items added to the Whitelist let mails pass regardless of what any other tests might result in.

You can add single mail addresses like joe@domain.com or pattern like joe@*, *@domain.com or even joe*.com.

Blacklist

The Blacklist is the reverse to the Whitelist: no item passes, regardless of what the tests might result in.

Hint: you might get the idea to add sender addresses of known but missed spam to the blacklist. This has two disadvantages: first the sender addresses change very fast and second the blacklist will be filled with permanent useless addresses (that slows down loading and checking and raises memory consumption). Instead use a Quickfilter and let it expire after 30 days.

Auto-Whitelist

If you get mail from certain senders on a regular base, this sender will be put onto the Auto-Whitelist. This will speed up message procession and avoid possible false positives.

The Auto-Whitelist has a trigger to add user (X mails from this sender within a certain number of days), an expire-age-setting for auto-deletion and a never-add-to-auto-whitelist-list.

Auto-Whitelist addresses mail is send to

Everytime you write an eMail the addresses are added to the Auto-Whitelist. So these recipients are never spam, if they write back to you. The aging feature of the Auto-Whitelist prevents the list from growing infinite.

Actually, if an item is on the White- or Blacklist, no other test is done.

It is possible to add IP-numbers to white- and blacklists, too. IP-numbers are not auto-whitelisted. But: a message normally has multiple IP-numbers listed in its header and all are tested against the white- and blacklist. So whitelisting 127.* for local IP-numbers might be an idea, but if the spammer adds a fake IP-number 127.0.12.3 the spam will pass.