[CentOS] DKIM

Thu Sep 25 16:46:54 UTC 2008
Bill Campbell <centos at celestial.com>

On Thu, Sep 25, 2008, Kai Schaetzl wrote:
>Ralph Angenendt wrote on Wed, 24 Sep 2008 20:23:50 +0200:
>
>> That's supposed to help with what regarding his problem?
>
>Hotmail seems to delete all mail from domains without SPF if it's not 
>coming from the MX. Yahoo might be doing the same.

I don't think this is the case as we host several Mailman mailing
lists with hotmail and yahoo subscribers, don't have SPF, and
would *NEVER* send mail from an MX IP (they're for receiving
mail, not sending it).  Where the same machine is receiving
messages as an MX, we configure postfix to listen on the MX IP
address and send on a different IP.  We also have postfix
configured to reject e-mail from servers that announce themselves
as one of our MX servers in HELO/EHLO as that is guaranteed to be
a spammer.

Checking one of these lists, I see quite a few hotmail and yahoo
addresses, all of which are getting mail from our server on a
regular basis.

Many of the large ISPs (e.g. AOL, Road Runner, etc.) have
feedback loops where one can sign up, providing an e-mail address
to address their customer's complaints, and a list of e-mail
servers from which your domain's mail originates.  The ISP will
send notifications when their customer hits the ``this is spam''
button.  In the case of AOL, this notification includes the
message with the recipient's address redactied, and they expect
you to cease sending messages to that address.  This requires
that one use VERP so that each outgoing message has the recipient
address somewhat munged in the headers so it's possible to
identify the correct address to remove.

We are on the AOL feedback, but not on hotmail or yahoo so
they're not accepting mail from our servers based on signing up
for the feedback.

Bill
-- 
INTERNET:   bill at celestial.com  Bill Campbell; Celestial Software LLC
URL: http://www.celestial.com/  PO Box 820; 6641 E. Mercer Way
Voice:          (206) 236-1676  Mercer Island, WA 98040-0820
Fax:            (206) 232-9186

Microsoft is to computers what Phillip Morris is to lungs.