Comments on: How to Setup DKIM for Postfix in Fedora using dkim-milter http://allaboutlamp.com/2009/09/setup-dkim-for-postfix-in-fedora-using-dkim-milter/ Create web applications with Linux, Apache, MySQL, PHP and other open source technologies Fri, 02 Jul 2010 14:40:24 +1000 http://wordpress.org/?v=2.8.4 hourly 1 By: Daniel Lam http://allaboutlamp.com/2009/09/setup-dkim-for-postfix-in-fedora-using-dkim-milter/comment-page-1/#comment-410 Daniel Lam Sat, 15 May 2010 02:59:22 +0000 http://allaboutlamp.com/?p=1#comment-410 Thanks for the information! Appreciate it! Thanks for the information! Appreciate it!

]]> By: ThomasRutter http://allaboutlamp.com/2009/09/setup-dkim-for-postfix-in-fedora-using-dkim-milter/comment-page-1/#comment-386 ThomasRutter Thu, 06 May 2010 14:24:29 +0000 http://allaboutlamp.com/?p=1#comment-386 Trailing blank lines seems to do it too. Looks like we have to be careful about filtering our mail before submitting it to PHP's mail() function. I expect there to be other things that trip it up. I think I'll abstract it out with a library. Trailing blank lines seems to do it too. Looks like we have to be careful about filtering our mail before submitting it to PHP’s mail() function. I expect there to be other things that trip it up.

I think I’ll abstract it out with a library.

]]> By: ThomasRutter http://allaboutlamp.com/2009/09/setup-dkim-for-postfix-in-fedora-using-dkim-milter/comment-page-1/#comment-385 ThomasRutter Thu, 06 May 2010 14:14:59 +0000 http://allaboutlamp.com/?p=1#comment-385 The "did not verify" problem when using PHP seems to be caused by email bodies containing the "\r" character. That is, a carraige return. Postfix's sendmail implementation expects line breaks to be "\n" only. Stripping these out before using mail() fixed the problem for me, and all emails verify DKIM properly with PHP posting to sendmail->postfix->dkim-filter I've seen problems before with PHP sending mail with "\r\n" instead of "\n". It's strange, because email itself wants "\r\n", however PHP (or sendmail) seems to expect "\n" only. Not sure how this affects things if you've configured PHP not to use sendmail. My guess is that PHP or sendmail is converting line breaks before dkim-filter, and dkim-filter sees a version with incorrect "\r\r\n" line breaks, then these are stripped out when the mail is transmitted, breaking DKIM's signature. Unfortunately dkim-filter's "relaxed" body verification doesn't mitigate this problem as it deals only with whitespace within a line - position and type of line breaks ignored. The “did not verify” problem when using PHP seems to be caused by email bodies containing the “\r” character. That is, a carraige return. Postfix’s sendmail implementation expects line breaks to be “\n” only.

Stripping these out before using mail() fixed the problem for me, and all emails verify DKIM properly with PHP posting to sendmail->postfix->dkim-filter

I’ve seen problems before with PHP sending mail with “\r\n” instead of “\n”. It’s strange, because email itself wants “\r\n”, however PHP (or sendmail) seems to expect “\n” only. Not sure how this affects things if you’ve configured PHP not to use sendmail.

My guess is that PHP or sendmail is converting line breaks before dkim-filter, and dkim-filter sees a version with incorrect “\r\r\n” line breaks, then these are stripped out when the mail is transmitted, breaking DKIM’s signature. Unfortunately dkim-filter’s “relaxed” body verification doesn’t mitigate this problem as it deals only with whitespace within a line – position and type of line breaks ignored.

]]> By: Daniel Lam http://allaboutlamp.com/2009/09/setup-dkim-for-postfix-in-fedora-using-dkim-milter/comment-page-1/#comment-100 Daniel Lam Thu, 31 Dec 2009 04:20:24 +0000 http://allaboutlamp.com/?p=1#comment-100 Good to know that it helped! Regarding the use of openssl - that was just because I was not aware of the dkim-genkey tool. Thanks for pointing out! Good to know that it helped! Regarding the use of openssl – that was just because I was not aware of the dkim-genkey tool. Thanks for pointing out!

]]> By: Henry Hughes http://allaboutlamp.com/2009/09/setup-dkim-for-postfix-in-fedora-using-dkim-milter/comment-page-1/#comment-33 Henry Hughes Tue, 24 Nov 2009 17:40:18 +0000 http://allaboutlamp.com/?p=1#comment-33 Brilliant article. Had me up and running on my test rig in no time, thank you. I'm curious as to why you mention using openssl command to create the keys, when you can use the utilities that comes with dkim-milter itself, eg: /usr/sbin/dkim-genkey -r -d mydomain.com This outputs 2 files, private and the exact string for TXT dns record. Incidentally, a bug has been reported regarding the permisions problem with the .sock file: https://bugzilla.redhat.com/show_bug.cgi?id=527423 ... unsolved as yet. Brilliant article. Had me up and running on my test rig in no time, thank you.

I’m curious as to why you mention using openssl command to create the keys, when you can use the utilities that comes with dkim-milter itself, eg:

/usr/sbin/dkim-genkey -r -d mydomain.com

This outputs 2 files, private and the exact string for TXT dns record.

Incidentally, a bug has been reported regarding the permisions problem with the .sock file:
https://bugzilla.redhat.com/show_bug.cgi?id=527423
… unsolved as yet.

]]> By: Setting up SPF, SenderID and DKIM on Centos 5.3 using sendmail | Mixu’s blog http://allaboutlamp.com/2009/09/setup-dkim-for-postfix-in-fedora-using-dkim-milter/comment-page-1/#comment-8 Setting up SPF, SenderID and DKIM on Centos 5.3 using sendmail | Mixu’s blog Tue, 03 Nov 2009 16:53:03 +0000 http://allaboutlamp.com/?p=1#comment-8 [...] Postfix, use these instructions from All About LAMP. If you want to use sendmail as I did, here are my additional [...] [...] Postfix, use these instructions from All About LAMP. If you want to use sendmail as I did, here are my additional [...]

]]> By: All About LAMP » How to Prevent Emails Sent from Web Server to be Marked as SPAM http://allaboutlamp.com/2009/09/setup-dkim-for-postfix-in-fedora-using-dkim-milter/comment-page-1/#comment-2 All About LAMP » How to Prevent Emails Sent from Web Server to be Marked as SPAM Tue, 29 Sep 2009 17:36:15 +0000 http://allaboutlamp.com/?p=1#comment-2 [...] to this article for implementation details of [...] [...] to this article for implementation details of [...]

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