I'm using Postfix to relay mail from my site to my mail server. Mail is received properly at my Gmail and Hotmail accounts - only Yahoo is the problem. The Yahoo mail headers state:

Received-SPF: none (mta1133.mail.mud.yahoo.com: domain of [email protected] does not designate permitted sender hosts)

In contrast, the Gmail headers state:

Received-SPF: pass (google.com: domain of [email protected] designates 74.50.xxx.xxx as permitted sender) client-ip=74.50.xxx.xxx;

Reverse DNS is set up correctly, as is my SPF record and domainkeys/dkim (both domainkeys and dkim show pass(ok) in the Yahoo mail headers).

Does anyone have any suggestions as to what I can do to solve the Yahoo problem (short of contacting Yahoo, as this is a brand new mail server)?


  • To check if your domain keys, send the message to a gmail account and look at the headers it adds... look for dkim=pass
    – Agos
    May 26, 2010 at 0:02
  • @Jed - Yes, that would have been a better place to ask. @Agos - I did verify that domainkeys=pass (ok) on Yahoo.
    – modulaaron
    May 26, 2010 at 0:09
  • 1
    I appreciate that you want to keep your keep your details private, but details about your network would be useful. It is pretty difficult to trouble-shoot an SPF issue when you haven't told us anything about your mail setup or SPF records. I would point out that yahoo reports none for SPF which makes me strongly suspect you have something wrong in DNS.
    – Zoredache
    May 26, 2010 at 2:24
  • @Zoredache - The domain mentioned is dev.vitalmtb.com and it relays mail to mta.vitalmtb.com using SMTP AUTH. The SPF record is published under the main domain vitalmtb.com and should allow validation for all subdomains (dev and mta included).
    – modulaaron
    May 26, 2010 at 3:02
  • I just created a more specific SPF record so as to not rely on the PTR directive for @ that allows all domains ending in the main domain to send. The new record for the dev subdomain alone is "v=spf1 a mx a:mta.vitalmtb.com ~all". Received-SPF is now "pass" for Yahoo, so that is working. However, the mail still goes into the spam folder with the message "X-YahooFilteredBulk:". To recap, SPF, reverse-DNS, and domainkeys/dkim are all working properly, the mail server (new) is not blacklisted, and Yahoo still refuses to behave.
    – modulaaron
    May 26, 2010 at 3:42

2 Answers 2


In MX Toolbox I get (for domain: vitalmtb.com): Warning - Reverse DNS does not match SMTP Banner (this could mean that PTR record for your domain is not correct or your HELO banner doesn't match your PTR record. Perhaps Yahoo doesn't like that? Good luck!

  • Forget about my answer sometimes serverfault pops up really old messages... and I didn't notice this one was really old when I typed my answer. Jul 16, 2012 at 22:38

Try this Email Server Test for suggested fixes.

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