I have installed DKIM-Filter on Postfix after reading this tutorial


My email now has a DKIM signature but still it is landing in the SPAM folder. Here is the header

    Received-SPF: neutral (google.com: is neither permitted nor denied by best guess record for domain of promote@a2labs.in) client-ip=;
Authentication-Results: mx.google.com; spf=neutral (google.com: is neither permitted nor denied by best guess record for domain of promote@a2labs.in) smtp.mail=promote@a2labs.in; dkim=hardfail (test mode) header.i=@a2labs.in
Received: from promote.a2labs.in (localhost [])
    by promote.a2labs.in (Postfix) with ESMTPA id 34858530E8
    for <vineet@ivineet.com>; Mon, 28 Feb 2011 12:23:07 +0530 (IST)
DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=a2labs.in; s=mail;
    t=1298875987; bh=bo+H1VYPIHMja2u7i1lnzr4k/j4Pe8iSf79bVw94XpI=;
     Content-Type:Content-Transfer-Encoding; b=nhTdlnUwo0iUJ92ycQzKSRjw

Also my mail.err file shows

Feb 28 12:17:03 ivineet dkim-filter[32181]: 1F788530E1: no signature data
Feb 28 12:18:02 ivineet dkim-filter[32181]: 432BA530E2: no signature data

How to fix it

  • Check that your dns txt records exist – topdog Mar 3 '11 at 15:44

Look at the line above the "no signature data", is says something like this:

Jul  4 10:33:46 pa04 dkim-filter[29984]: 9A95B340F6C external host localhost.localdomain attempted to send as mydomain.com
Jul  4 10:33:46 pa04 dkim-filter[29984]: 9A95B340F6C: no signature data

If so, create file /etc/postfix/dkim/hosts with list of hosts who's email to sign and add to the /etc/dkim-filter.conf the following lines:

ExternalIgnoreList      /etc/postfix/dkim/hosts
InternalHosts           /etc/postfix/dkim/hosts

What is the value of "Domain" in your dkim-filter.conf? I experienced the same problem when stating the actual domain, and it was fixed by rather using a wildcard.

from 'Domain mydomain.com' to 'Domain *', leaving selector and KeyFile intact.

Hope it helps.

  • +1 Simpler solution. – kubanczyk Nov 19 '15 at 9:53

Here is answer click : a=rsa-sha256 => a=rsa

And you dont have spf record: bind9:

mail.example.com.          IN      TXT "v=spf1 a mx -all"


mail.example.com.          IN      SPF "v=spf1 a mx -all"

this means deny all mail without A record fro MX entry (something like this)

  • rsa-sha256 seem to work for me. – 3molo Apr 7 '11 at 8:15
  • and this doenst work for me with yahoo or google. i used rsa-sha1 rsa-sha256 – MealstroM Apr 7 '11 at 8:40

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.