feature request: read/write/append entire whitelist

Today for the second time in two years I've accidentally reported mail 
from someone I know as SPAM.  That's an error rate of 2 in something 
like 140,000, but low as it is it causes some grief.  It happened 
because his work address was not on my whitelist.  This was apparently 
the first time mail form him there was classed as SPAM by the filters.

Clearly this was human error on my part (I missed the message when I 
scanned Held Mail), but I can see some things that would help avoid this 
in the future.

I really need everyone in my address book on my whitelist.  Actually, 
like most of us, I have several address books across several computers 
so I need to be able to add whole address books to the whitelist.  These 
change, so I need to be able to do it either automatically, or at least 
without dozens or hundreds of manual steps, as there are now.

One simple mechanism would be to accept a whole list in the "add to 
whitelist" page instead of single addresses in separate boxes.  This box 
would have an "add to whitelist" as well as a "replace whitelist" 
button.  The add (or append) option would of course remove duplicates 
(|sort|uniq) from the result.  We'd also need a "download whitelist" 
button that links to a text/plain file containing the whole list.  These 
simple mechanisms would give us everything we'd need to keep whitelists 
synchronized with address books either manually, or with wget in some 
simple scripts on our end.  Who knows, maybe someone will even cook up a 
Thunderbird add-on to do this automatically.

As a stretch goal, I'd also like the ability to re-apply the whitelist 
to the Held Mail folder when the whitelist is changed.  Any messages 
matching the updated whitelist would be released to the Inbox.

I don't use my blacklist, but similar features for the blacklist may be 
useful for those that do.

--- sdp