RBL & greylisting on Ubuntu.com smtp

[Jan Claeys]

Op za, 17-06-2006 te 11:26 +0200, schreef Lionel Dricot:
> I don't know about you, but my ubuntu.com mail address is full of
> spam. Really really full !
> 
> I was wondering why RBL checking and greylisting wasn't working until
> I realize that all this spam go through de ubuntu.com smtp first !
[...]
>         reject_rbl_client cbl.abuseat.org,

>From their site:

        News (2006/06/15): NEWS ALERT
        For a brief period from approximately 4:10 to 6:00 UTC on June
        15th, a number of entirely erroneous CBL listings occured due to
        parsing problems in a new CBL process.

>         reject_rbl_client dul.dnsbl.sorbs.net,
>         reject_rbl_client dynablock.njabl.org,

Recently, one of those idiots (or a similar list) listed my ISPs whole
*server* netblock as being used by "dynamic/dialup IPs".

All those blacklists can easily be abused (and _are_ abused), and when
that happens, or when an error occurs, a lot of innocent people will be
affected.  Blacklists are evil when you use them to block mail.  (You
can probably use the better ones to add some amount in a spam scoring
system though.)


Greylisting has some problems too (mostly delays), but AFAIK they are
smaller than those caused by blacklisting.


-- 
Jan Claeys