ok2 env_to possible?

John Sutton john@scl.co.uk
Mon Mar 8 22:37:09 UTC 2004

On Monday 08 March 2004  9:17 pm, you wrote:
> > As I read it, at present we have for "ok2 env_to":
> >
> > with -W : special meaning (kludge)
> > w/o -W: no meaning i.e. completely ignored
> >
> > so would it not be possible to move to:
> >
> > with -W : special meaning (kludge)
> > w/o -W: "proper" meaning
> >
> > without breaking any existing installations (excepting those which have
> > currently meaningless "ok2 env_to" rules in place)?
> That would require substantial changes in the code.
> Currently env_to checksums are not looked at anything except the
> code that decides whether the mailbox is playing the DCC game.
> Having the 'proper' meaning would require passing env_to checksums
> to other places that compare thresholds and so forth.
> Since most people view the 'proper' meaning of OK2 as a bigger kludge
> than the -W business, that doesn't seem very profitable.
> For your situation, why not use "ok env_to" to opt that mailbox
> out of the DCC game entirely?

What I have (attempted to) implement is as follows.  In addition to:

ok2 ip localhost

I am automatically generating a file called virtusertable.dcc which is 
included by whiteclnt and which consists of all lhs's from virtusertable 
prefixed by "ok2 env_to".

Thus (if it was working as I'd hoped ;-), any cgi or modphp script which 
sends to a virtusertable user will pick up 2 ok2's and so such messages will 
be whitelisted.  This is necessary not only for privacy reasons but also 
because many such scripts send exactly the same message repeatedly e.g. "A 
new order has been placed on your web site.", etc, and so must NOT be 
reported because they are "bulk".  OTOH, as happens frequently, when some 
spammer find and hijacks a customer's cgi script, e.g. the notorious 
formmail.pl, the submissions made by the script will *not* be whitelisted 
(since the recipients will not predominantly if at all be virtusertable 
users) and so these messages will (in due course) be blocked by a DDC 
checksum report.

In short, if my reasoning is sound and if ok2 env_to were not broken, the DCC 
would solve the problem of cgi spam which is a major headache to me.

John Sutton
SCL Internet
URL http://www.scl.co.uk/
Tel. +44 (0) 1239 711 888

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