[spambayes-dev] Results for DNS lookup in tokenizer

[Tony Meyer]

> Like x-slurp_urls, enabling this option could allow host 
> names to be used as a bug by spammers to determine whether
> an email address is live. That doesnt seem likely, but its
> not impossible.

This was discussed (a lot) back when the x-slurp_urls option was first
offered.  It's probably the main reason why even if it does live past being
an experimental option, it'll never default to True.  It's also the reason
for the x-only_slurp_base option - I can't see any way (other than
registering a domain per message) that it could then be used as a 'address
is live' indicator.  OTOH, enabling x-only_slurp_base does a lot of hurt to
the results in my testing.  If the x-slurp_urls option is ever shown to be
really effective, then it seems likely that a middle path between the two,
where it's very difficult to put any tracking information in, could be
created easily enough.

> A barely related question..... which of our filtering methods 
> allow for parallel filtering? sb_filter out of procmail does,
> provided your mta runs procmail concurrently :-) but sb_bnfilter
> will serialise them again :-(

I'm pretty sure that we don't support more than one process accessing the
database at one time at all.  As for one process filtering multiple messages
at a time, I believe sb_server can do this (i.e. if two connections are
made, to different local proxy ports, at the same time).  sb_imapfilter and
the Outlook plug-in don't.

I do have a version of the testing setup than runs on a cluster, but I
presume that's not the sort of parallel you were meaning?

=Tony Meyer