RBL & greylisting on Ubuntu.com smtp

[Lionel Dricot]

Hello Jan,

> >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.)

Perhaps not the best way. But at least mail are not lost because the
sender is notified with "you are in the XXX blacklist.
>
>
> Greylisting has some problems too (mostly delays), but AFAIK they are
> smaller than those caused by blacklisting.

I had doubt about greylisting but I'm really surprised by how good it
is. In fact, it takes approximately one day to completely forgot
delays. The first day, mails could be delayed (from 5 minutes to two
hours. Most of them are received with 1/4h delay at max).
After the first day, you won't notice any delay anymore, I'm really surprised.


Anyway, I think having some sort of spam filtering on fiordland could
be a good thing. It would even save bandwidth (as each spam received
for an @ubuntu alias is then sent to the real address.  My ubuntu.com
address is not widely advertised but you cannot imagine how much spam
I receive on it, even after spamassin filtering on my server. It's so
sad...

And if you are using Evolution, you can't really rely on the client
side filtering ;-)