Yahoo and their mail filters..

Suresh Ramasubramanian ops.lists at
Wed Feb 25 04:31:52 UTC 2009

With a large enough userbase, misdirected spam complaints become far
less of a factor.

Lets put it this way .. one or two users can forget and report the
same email as spam.  If a whole bunch of users do that, not just a
few, then either two things.

1. You have a problem


2. There's a mass outbreak of alzheimers and all our users forgot

Again - that's with a large enough userbase and with marketing content
sent in bulk.

Deliverability problems for lower volume is tougher to troubleshoot
and it could be because of various other reasons than just complaints.

--srs (mailops IS operational and belongs on nanog)

On Wed, Feb 25, 2009 at 9:56 AM, Stefan Molnar <stefan at> wrote:
> For our userbase with yahoo/hotmail/aol accouts they hit the spam button more often than delete.  Then complain they do not get emails anymore from us, then want discounts on a bill of sale they missed. It is a never ending story.
> ------Original Message------
> From: Suresh Ramasubramanian
> To: Micheal Patterson
> Cc: nanog at
> Subject: Re: Yahoo and their mail filters..
> Sent: Feb 24, 2009 7:59 PM
> On Wed, Feb 25, 2009 at 9:23 AM, Micheal Patterson
> <micheal at> wrote:
>> SPF records aren't being recognized, I've been running them for some time
>> now so it would seem that they're not honoring them.
> Christ .. Yahoo did say "complaints".  And it can take a very low
> level of complaints before a block goes into place - especially for
> low volume (corporate etc) mailservers.
> Feedback loops are one cure, and another cure is keeping complaint volumes down.
> * Do you have an unfiltered NAT gateway pointed to the same IP as your
> corporate MTA?
> * Do you have any large spam sources in close proximity to you?  Like
> you are colo'd on a /28 and someone else has a /27 or /26 in the same
> /24 that's emitting tons of spam (assuming colo).  Or you have your
> mailserver hosted on a dsl pool (even a business class dsl pool) in
> which case your server is an island of valid mail in a large swamp of
> virus traffic
> * Do you have a marketing department that might be slightly overactive?
> etc etc.
> srs

Suresh Ramasubramanian (ops.lists at

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