[67551] in North American Network Operators' Group
Re: SMTP authentication for broadband providers
daemon@ATHENA.MIT.EDU (Suresh Ramasubramanian)
Wed Feb 11 20:48:57 2004
Date: Thu, 12 Feb 2004 07:18:18 +0530
From: Suresh Ramasubramanian <suresh@outblaze.com>
To: Will Yardley <william+nanog@hq.dreamhost.com>
Cc: nanog@merit.edu
In-Reply-To: <20040211201901.GB17951@hq.newdream.net>
Errors-To: owner-nanog-outgoing@merit.edu
Will Yardley wrote:
> My understanding is that in most cases, providers are blocking port 25
> outbound to prevent direct to MX spamming from their customers' machines
If you do that, please put in a corresponding ACL to block port 25
inbound _and_ outbound.
Otherwise, you just might get bitten by something like spoofed source
routing, as several providers have found out in the past.
srs
