I've always had intermitent issues with delivery to Yahoo email addresses. In recent months it's gotten just plain ridiculous. They are essentially doing derferment of delivery until you buy into their DomainKey sigining, even after filling out their form and the tell you that your delivery issues should be fixed. Yahoo is not giving me the warm-fuzzies - I still get 20-30 pieces of spam a week, which are all domainkey signed. In recent history Yahoo seems to have gotten a little too overzealous.
- This Is True Deferral/Blocked
- answers.yahoo.com - Temporary Deferral 1
- webhostingtalk.com- Temporary Deferral 2
- support.viux.com - Temporary Deferral 3
- smartertools.com - Temporary Deferral 4
- smartertools.com - Temporary Deferral 5
Even after confirming that reverse DNS was configured and creating an SPF record, I was still getting delays of 24-48 hours. SmarterMail 3 only lets you have 4 retries, so I created a scheduled batch file to restart the service every 8 hours (resets the attempt counter) and set the last spool attempt far enough in the future that the email would still be in the spool when next 8 hours came along. My mail delivery logs were filling up with attempts which were deferred.
02:08:26 [27088] Sending remote mail for <USER>@carrotware.com
02:08:26 [27088] Connecting to 206.190.53.191
02:08:26 [27088] Connection to 206.190.53.191 succeeded
02:08:26 [27088] RSP: 421 Message from (64.38.49.208) temporarily deferred - 4.16.50. Please refer to http://help.yahoo.com/help/us/mail/defer/defer-06.html
02:08:26 [27088] CMD: QUIT
I had also confirmed that I was not on any RBLs and not operating an open relay, still my emails were being delayed. I made sure I had the sending email account in the address book, still didn't work. I submitted a ticket with the postmaster team, they responded with a form which I submitted and they then notified that me they couldn't whitelist me, but they did do something to reduce deferrment. Whatever they did was not permanent.
Thank you for writing to Yahoo! Mail.
We have made appropriate changes to the IP address you have submitted within our database. However, we cannot fully exempt your mail server from our SpamGuard technology. This should help with delivering mail to the appropriate Yahoo! folders.
Please be aware that Yahoo! Mail users are able to set their own preferences for the manner in which they receive your mailings. If the recipients of your messages want to ensure they receive your emails in their Inbox, you may want to ask them to set up a filter in Yahoo! Mail specifically for your emails, or have them add your email address(es) to their Yahoo! Address Book.
Please refer to the Help page below for more information on our recommended best practices for sending mail from any mail server to Yahoo! Mail users.
I'm not ready to shell out the $190 to upgrade to SmarterMail 5, so I installed DKeyEvent to perform domain key signing. There is a really easy to follow video for installation and configuration of keys here. I'll also note here that I have also sent messages to Hotmail, AOL, Comcast, and GMail accounts and not a a single missive had to be retried more than once to deliver - ever.
Inserting the necessary keys into DNS is also pretty easy. My hosting company uses the DNS zone editor within Parallels Business Automation (HSPcomplete). I created both domainkey and selector entries as shown below.
Next thing to tackle was that I had a custom email client which I wrote and had always had issues with authenticated SMTP so I had gone with just whitelisting the server which hosted the mail client as the app had front-end authentication. When I recently migrated my sites from Dot Net 1.1 to 2.0, I got numerous warnings from the compiler about using System.Net.Mail instead of System.Web.Mail (Warning 9 'System.Web.Mail.SmtpMail' is obsolete: 'The recommended alternative is System.Net.Mail.SmtpClient. http://go.microsoft.com/fwlink/?linkid=14202' N:\sandbox\WebMail2\Compose.cs 282 4 WebMail ). So I dutifully updated the relevant code to the recomended framework library. Unfortunately, afer implementing the new framework, domain keys no longer work reliably, this could seemingly be because of the "prefered" framework using lowercase instead of mixed case (microsoft, deusblue, directorym, blogspot) for the email headers as this behavior has created issues with other applications as well.
Once I went back to using System.Web.Mail and using the CDO headers for authenticated SMTP, all was well. The interesting here is when I sent a short email of 1-2k to validator email addresses using the native 2.0 mail framework, but if I then sent another longer email, say holding the entire text of "Paul Revere's Ride", the keys would fail.
I sent to responder check-auth[at]verifier[dot]port25[dot]com and got success messages with either short System.Net.Mail message, any length System.Web.Mail generated message, native SmarterMail web client generated message, or a third party Windows mail client generated message, like Eudora 7:
==========================================================
Summary of Results
==========================================================
SPF check: pass
DomainKeys check: pass
DKIM check: pass
Sender-ID check: pass
SpamAssassin check: ham
using System.Web.Mail SMTP sending with this header:
DKIM-Signature: v=1; t=1225656248; a=rsa-sha1; q=dns/txt; s=selector3;
d=carrotware.com; i=[USER]@carrotware.com; c=relaxed/simple; bh=Mv5zqn4
pQol8nuDcEf9tL4tMBW4=; h=DomainKey-Signature:X-Originating-IP:
Thread-Topic:X-Mailer:Message-ID:thread-index:From:To:Cc:Subject:Date:
MIME-Version:Content-Type:Content-Transfer-Encoding:Content-Class:
Importance:Priority:X-MimeOLE; b=qgnqyJ7eUc2fiGd/Xlynl/SK0V/+2/dMiM+pgeev
XFGAPCS2yBhGdHWN3ITMb3NOxYm6xQcRw5UEwqRCRcD2w33DrxTkt0qwdagMxzDd5eMi93Vt1
rgwUR+9Cj8zwdhE
DomainKey-Signature: a=rsa-sha1; q=dns; s=selector3;
d=carrotware.com; c=nofws; h=Received:X-Originating-IP:Thread-Topic:X-Mai
ler:Message-ID:thread-index:From:To:Cc:Subject:Date:MIME-Version:Content-
Type:Content-Transfer-Encoding:Content-Class:Importance:Priority:X-MimeOL
E; b=CRajWBHNVvkHoY9cH7S8pOO9LZrjixCGuU08kqKP4Iqrd3ikN/dY5c5TzieTvKR2/m3H
teWpVC2HwG10h3DTN6SG3NedPAQluOEgSM7psL3KdxatZp6o0DzUWKRE6fB9;
Return-Path: <[USER]@CARROTWARE.COM>
Received: from CT423.carrotware.com [64.38.49.208] by mail.carrotware.com with SMTP;
Sun, 2 Nov 2008 14:03:33 -0600
X-Originating-IP: 68.52.249.226
Thread-Topic: Paul Revere's Ride 3
X-Mailer: carrotware.com mail client v3.0.3228.24827
Message-ID: <000101c93d26$151f1560$d0312640@CT423>
thread-index: Ack9JhUfDal5TWVFSFulsHIPFbDccQ==
From: "samantha copeland" <[USER]@CARROTWARE.COM>
To: check-auth[at]verifier[dot]port25[dot]com
Cc:
Subject: Paul Revere's Ride (2)
Date: Sun, 2 Nov 2008 14:03:32 -0600
MIME-Version: 1.0
Content-Type: text/plain;
charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
Content-Class: urn:content-classes:message
Importance: normal
Priority: normal
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.3790.2992
sending with System.Net.Mail a message longer than 3k:
==========================================================
Summary of Results
==========================================================
SPF check: pass
DomainKeys check: fail
DKIM check: pass
Sender-ID check: pass
SpamAssassin check: ham
DKIM-Signature: v=1; t=1225653115; a=rsa-sha1; q=dns/txt; s=selector3;
d=carrotware.com; i=[USER]@carrotware.com; c=relaxed/simple; bh=NrPZjPL
D8CY4SMGFo/FmD2ywQMI=; h=DomainKey-Signature:x-originating-ip:x-mailer:
mime-version:from:to:date:subject:content-type:content-transfer-encoding;
b=f2Ry9DwFIaxh7AVMga+NpgdG1luLEt6amn7WPry6wNFK5sXdhVz3Zj2JaaqaWu6oSvjzjA0
0xPMBMLYQjmgPJUdP3lH48O1ou7v/lldBdr76aS9ifS0EDr+A+xNhQskp
DomainKey-Signature: a=rsa-sha1; q=dns; s=selector3;
d=carrotware.com; c=nofws; h=Received:x-originating-ip:x-mailer:mime-vers
ion:from:to:date:subject:content-type:content-transfer-encoding; b=SY+eZ8
asSp8264BpsxJoBKHuCRLGK5wPY+/AFQA85GwvR0RETWsIdlevSsrGpxffiiK4IH7WeuSGNfD
ttsBQBzM+rsXnBnUFUuBpIGBfrNxWffUT/VfSKXAMpN276eCS;
Return-Path: <[USER]@CARROTWARE.COM>
Received: from CT423.carrotware.com [64.38.49.208] by mail.carrotware.com with SMTP;
Sun, 2 Nov 2008 13:11:19 -0600
x-originating-ip: 68.52.249.226
x-mailer: carrotware.com mail client v3.0.3227.37422
mime-version: 1.0
from: "samantha copeland" <[USER]@CARROTWARE.COM>
to: check-auth[at]verifier[dot]port25[dot]com
date: 2 Nov 2008 13:11:19 -0600
subject: Paul Revere's Ride (1)
content-type: text/plain; charset=iso-8859-1
content-transfer-encoding: quoted-printable
Message-Id: <490DFAA9.00000006@verifier.port25.com>