RE: ingress SMTP

["Frank Bulk" <frnkblk () iname com>]

How do you alert mail server operators who are smarthosting their e-mail
through you that their outbound messages contain spam?

Frank

-----Original Message-----
From: Matthew Moyle-Croft [mailto:mmc () internode com au] 
Sent: Saturday, September 13, 2008 12:41 AM
To: Bill Stewart
Cc: nanog () nanog org
Subject: Re: ingress SMTP

Hi Bill,

Bill Stewart wrote:
> In some sense, anything positive you an accomplish by blocking Port 25
> you can also accomplish by leaving the port open and advertising the IP
> address
> on one of the dynamic / home broadband / etc. block lists,
> which leaves recipients free to whitelist or blacklist your users.
Except that this tends to lead to a worse situation for people like
yourself who wish to run a mailserver - because ultimately you'll have
to resort to using an ISP's forwarder anyway because there will be more
spam from the IP ranges you're in leaving to the wide world, thus a
worse reputation, and so more blocking.

ie.  by blocking outbound SMTP by default and getting customers to use
our mail cluster their email is more likely to arrive and not be dropped
as coming from a potential spam source.

> I've toned down my vehemence about the blocking issue a bit -
> there's enough zombieware out there that I don't object strongly to an ISP
> that has it blocked by default  but makes it easy for humans to enable.
That's what we do - by default most customers have a small ACL applied
which protects them from traffic from various windows ports, ensures
SMTP goes via our mail cluster etc.   Having customers send mail out via
us is actually better because we do spam checking and can alert
customers to their machines being compromised etc (or at least customers
can look at their status themselves).   But, customers can easily turn
the filtering off via the portal we have.

We have no issues with customers running servers - most people don't,
and those who do value the ability to do so.

MMC

--
Matthew Moyle-Croft - Internode/Agile - Networks
Level 4, 150 Grenfell Street, Adelaide, SA 5000 Australia
Email: mmc () internode com au  Web: http://www.on.net
Direct: +61-8-8228-2909             Mobile: +61-419-900-366
Reception: +61-8-8228-2999          Fax: +61-8-8235-6909