Spam and sieve vacation

[Janne Peltonen]

On Fri, Aug 24, 2007 at 07:47:28AM -0400, Jorey Bump wrote:
> > The policy in our university has long been to discourage using auto
> > responders (two of the main reasons being, we don't want to end up
> > forwarding spam to innocent third parties, and neither want to
> > automatically confirm to a spammer that an address works - auto-answers
> > to lists and other traditional pitfalls are more easy to avoid).  So we
> > don't support sieve vacation, either.
> > Now I'd like to ask the people on this list about their experiences
> > using the sieve vacation module. The risks of automatically
> > responding to spam / automatically forwarding spam / ending up in
> > sorceror's apprentice mode / ending up having our mail servers
> > blacklisted as spam relays - would they be acceptably low?
> 
> The risks are dependent on how effective your antispam measures are. If 
> you find that your institution is still delivering a high amount of spam 
> to user inboxes, it might be wise to continue the ban on autoreponders.

Well, abt 96% of all the mail we receive (or tries to reach us) is
recognized as spam, either blocked at smtp level (using blacklists) or
tagged as such by spamassassin & friends. It's harder to give a measure
on how much of the remaining 4% is still spam, for obvious reasons. ;)
There is some spam trickling through all the time, and when spammers get
innovative, the amount of spam that ends up visible to the users will
grow for a while. About 1 message in 50 that I actually see in my INBOX
is spam.

The problem is, of course, that the spam that isn't classified as such
isn't classified as spam because it's hard to automatically classify it
as spam. So, even if sieve vacation won't answer suspicious messages,
it would probably answer the spam it sees...

> If you don't get much spam, sieve vacation is suitable.

But how much is much, in your opinion? Say, 4 spam messages per day per user,
with 50 000 users? Would that be much? If, during summer, 25% of our
users were to have vacation active at any given time, that'd result in
50 000 vacation spams per day...

> Providing a usable frontend for ordinary users is the real challenge.

So it is.

Thanks for your insights.


--Janne
-- 
Janne Peltonen <janne.peltonen at helsinki.fi>