Yahoo and their mail filters..

Wed Feb 25 03:59:00 UTC 2009

On Wed, Feb 25, 2009 at 9:23 AM, Micheal Patterson
<micheal at spmedicalgroup.com> 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