whitelist_to getting exploited

[John Van Ostrand]

On Fri, 2006-12-29 at 19:34 +1000, Res wrote:
> On Fri, 29 Dec 2006, Ramprasad wrote:
> > Now a spammer marks a mail to multiple people with user-1  in BCC and
> > the mail passes straight
> > How can I get rid of this problem. If I use the user_in_whitelist_to
> > feature at spamassassin then too I would have the same issue
> 
> MailScanner is doing exactly what you have told it to, you either 
> whitelist user-1 or you don't, you can extend this to using the
> format of 'from and to' but that will be a restricted list, unless you
> are going to waste time constantly adding all the people he wants mail 
> from in the 'and to' segment.
> 
> The cure  Ram is to remove him from the To: whitelist

Have you considered using "Use Default Rules With Multiple Recipients =
yes". 

If that's a problem because you want an absolute whitelist on emails to
that user then there are sendmail techniques I've heard of split
messages when addressed to multiple recipients.

-- 
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