Post by LuKremePost by RWPost by LuKremeAnd, if not, is it generally better to do sitewide?
It's hard to say, there are advantages and disadvantages either way.
OK, so specific example then.
Small server with a few dozen email users spread over several
domains. Almost none of these users does any spam training at all,
the rest just delete unwanted messages (not even marking them as
junk) or even worse, just ignore them. One user is very aggressive in
marking Spam and in keeping the Inbox clear of all spam.
I am of two minds. First, that everyone else would benefit from this
user’s actions or, alternatively, that the user’s aggressive tagging
will actually ‘poison’ the bayes db for the other users who maybe do
not think that endless emails from pinterest or some political
candidate are actually spam.
For starters your problem isn't SPAM it's HAM.
You can get all the spam you want. Just parse the mail log file every
day for a few weeks, looking for delivery attempts to nonexistent
mailboxes. When you see repeated delivery attempts to a specific
mailbox then create an email address on that nonexistent mailbox and
redirect all the email into it into a spam box
My experience is that once spammers think they have "discovered" an
email address they will never leave it alone, they will send increasing
amounts of spam to that address.
If you are lucky enough to never have spammers trying to probe your
server, you can create your honeypot email addresses, just make them up,
and then take these email addresses and post them into the Unsubscribe
links on spam. That is a good way to contaminate spammers mailing lists
with honeypot addresses. A legitimate mailsender will ignore these, a
spammer will happily pull addresses out of unsubscribe replies.
That's your centralized spam source. Do this for a couple dozen
nonexistent email addresses on your server domains and you will have
all the input you want for the Bayes learner.
By definition ANY email to a nonexistent address (not an old address
that was closed down years ago) is unsolicited, AKA SPAM.
As for desired political mail, on my servers I classify all of it as
spam, I can think of maybe only 2 users over the last decade who have
complained about not getting it and for those it's easy to do an
all_spam_to to them and then tell them they will have to do their own
spam filtering.
Since overwhelmingly the political email I have seen coming in is the
offensive conservative anti-women, anti-blacks, anti-latinos, beg for
more money email, I have to say that I'm not particularly concerned
about the wishes of customers who WANT that kind of mail - I'm quite
happy if they go find another provider.
And, naturally, that kind of email is never ever appropriate for a
business and no employee in a business is ever going to dare complain to
their bosses that they aren't getting it.
If the politicos want to drown people in hate mail, they have paper
mail to do it - might as well make them help reduce my taxes by
subsidizing the US Post Office with their hate mail, that's about the
only thing that's good about it.
Anyway, as I said HAM is the problem. If you don't have large
quantities of ham, Bayes won't work. Of course, nothing is preventing
you from copying people's folders (if they are using IMAP) into one
giant mailbox and using that as a HAM source. You can probably assume
that if a user has gone to the trouble of saving mail to a folder that
it is ham.
Ted