Re: How would you provide a 554 rejection notice for spam?

[mouss]

Rick Macdougall wrote:

simscan correctly uses an SMTP REJECT (55x code during the smtp 
conversation) and it is also possible to use custom reject messages 
with simscan so the sender, if any, knows exactly why the message was 
rejected.

I have yet to see a good implementation of this in Postfix or 
Sendmail, and is one of the reasons I stick with Qmail.

running SA at smtp time requires that the client does not timeout. so 
you'd better scan fast! you're also more subject to DOS (your smtp 
listeners are busy). compare this to queue and filter...

anyway, you can still do smtp time filtering with postfix and sendmail. 
google for milter and proxy_filter.



Having to /dev/null spam and/or viruses to the end user is even worse 
IMHO (as an ISP, it might be acceptable in an office env where you can 
train the users to look at spam or virus folders).

Reject (not bounce) is acceptable, but you'd better configure your 
filter correctly. If I get a reject from you for a legitimate mail I 
sent, you will just make yourself ridiculous... It also delays 
legitimate mail (because I have to resend).

delivering to a Junk folder and letting the recipient review this folder 
maybe annoying, but if the recipient is not too dumb (or too busy), then 
he can "save ham transparently".

anyway, each site has its own policy for handling spam. What we ask is 
to avoid bad practices that result in annoying others (backscatter, C/R, 
... etc). The rest (discard, reject at smtp time, quarantine, ...) is up 
to you, your boss, your users, your customers, ... etc.