Recommended spam.lists and/or sendmail dnsbl settings?

[Scott Silva]

on 12/4/2007 6:22 PM Duncan, Brian M. spake the following:
> Thanks for confirming that for me.
> 
> So is this not a feature that would benefit many users?
> 
> The capability to have MailScanner NOT check ALL RBL's but in an order
> based on how many the admin wants till it equals a failure?
> 
> It seems kind of inefficient to check ALL RBL's listed if an admin
> trusts results from specific RBL's.
> 
> Like in my case I could avoid probably 80% of my queries to zen with
> this capability.
> 
> "The Spam Lists To Be Spam" directive could still be set, but
> MailScanner could quit RBL checks after meeting that condition.
> 
> It could even increase performance couldn't it for heavily loaded mail
> servers?
It would actually lower performance as each message would have to be checked 
one at a time one list at a time instead of firing off multiple queries and 
looking at the hits afterward. Think of telling a joke in a room full of 
people. Do you tell one person at a time and wait for a laugh (or not), or do 
you tell groups of people at the same time?
If a sysadmin trusts a list that well, he/she usually uses it at the MTA. That 
is the only way to really cut the load, because no further processing is done 
on it. The batch processing is what puts mailscanner ahead of the other 
options like mimedefang or amavisd (or ???).

> 
> In my organization we rely on MailScanner to do the RBL checks and pass
> ALL mail through to end users (We need to, they can never afford to miss
> a message)  RBL failed messages are considered high scoring spam and get
> a slightly different identifier to quickly identify an RBL'ed messages
> from one that failed do to message content.
> 
Since you forward all messages, you could have some preprocessor do rbl checks 
and add headers and then get mailscanner to not re-scan those.

In my organisation, if they are on a trusted RBL, they only send spam. 
Otherwise the un-trusted RBL's are scored with spamassassin like other 
content. That way a message in a less than reliable list, with no other 
content problems will usually get through unmolested.


-- 
MailScanner is like deodorant...
You hope everybody uses it, and
you notice quickly if they don't!!!!