Re: Suddenly Emails Bouncing

From: Jean-David Beyer (jdbeyer_at_exit109.com)
Date: 10/20/05 

Date: Thu, 20 Oct 2005 07:52:30 -0400

Robert M. Riches Jr. wrote (in part):

> Then, certain misguided, snobbish souls decided they would refuse to
> accept direct email from any machines other than certain "blessed"
> machines, mostly ISP outbound/outgoing mail servers. In particular, they
> make lists of blocks of IP addresses used for dynamic IP DSL and refuse
> to accept direct email from IP addresses in any of those blocks. Often,
> the makers of the lists claim innocence, because they just make the lists
> but don't directly refuse any email delivery. (They only advertise their
> over-broad lists as ways to reduce spam.)

I am one of these "snobs" who refuses e-mail from a couple of these lists
using blackhole lists. It does not eliminate spam, but it does reduce it. My
Mail Transfer Agent (MTA, sendmail) is set up to log each dropped e-mail and
I get a summary of dropped e-mails each day (with _logwatch_). In the years
I have been using it, it has never dropped a non-spam e-mail for me. I also
use the _access_ filtering of sendmail to drop whole countries (e.g.,
Brazil, China, Korea), and some overspamming ISPs (e.g., hotmail). This
reduces my spam load to a few dozen a day.
>
> Given that the blocklisters/blacklisters/snobs are firm in their
> misguided convictions that the way to beat spam is to prejudicially
> refuse direct email except from certain "blessed" hosts,

I do not consider that a proper characterization in that there is no
whitelist in the way I do things. There are blacklists. So I accept all
e-mail except for that coming from blacklisted senders. True, IP addresses
that do not resolve in DNS are among them, and these are typically dial-up
blocks of IP addresses voluntarily supplied by various ISPs. Also in the
lists are know open relays, etc., widely used by spammers.

> the solution is you have to send through a "blessed" host.

Since my machine resolves in DNS, I do not bother to send e-mail through my
ISP's mail server (these UseNet posts _do_ go through their news server,
though), and my e-mails do not seem to get bounced.

> For a while, I used a Perl script I called "sendsnob" that would send
> email through my ISP's "outgoing" server. Later, when the number of
> snobs grew, I reconfigured postfix to use the transport table to route
> messages intended for certain destinations through the ISP's "blessed"
> outgoing server, using what I call a snob list.

Seems like a lot of work. Why not just get a static IP address that resolves
in DNS?

> Another option is to configure your mail client (mutt can do this) to
> send through your ISP's "blessed" outgoing server.
>
My mutt is not set up to do that. It just sends everything through
localhost's MTA, and the MTA worries about such things for all Mail User
Agents (such as mutt, /bin/mail, etc.). 

-- 
  .~.  Jean-David Beyer          Registered Linux User 85642.
  /V\  PGP-Key: 9A2FC99A         Registered Machine   241939.
 /( )\ Shrewsbury, New Jersey    http://counter.li.org
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