A blog for odd things and odd thoughts.


Update to the Summary of the Summary

If you upgrade WordPress to 2.2.1 or higher, then you don’t need to read any further!

This plugin is now obsolete

Summary of the Summary

CRCRLF is an obsolete WordPress plugin.

If you read WordPress emails in Microsoft Outlook and don’t want to upgrade to the latest WordPress, you want this plugin.


WordPress and WordPress plugins automatically send emails to administrators, authors, commenters and subscribers.

WordPress 2.0 and 2.1 have a defect in the way they format emails.

WordPress 2.2 no longer has this defect! You don’t need this plugin if you upgrade WordPress to the latest!

The defect only occurs sometimes. It occurs when WordPress is being hosted on a Unix platform, including Linux. It does not occur when WordPress is hosted on a Windows platform.

Most email clients handle the defect without displaying any symptoms. The defect is only visible when anyone who receives the email (including administrators, authors, commenters and subscribers, depending on the active plugins) is running Microsoft Outlook.

In Microsoft Outlook, there are two symptoms:

  • Paragraphs are run together.
  • The first few lines of the email may contain cryptic header information, like the character set, e.g.

    Content-Type: text/plain; charset=”UTF-8″

The CRCRLF plugin patches this defect. It ensures that the emails are formatted properly by WordPress.

More details

I have published a more detailed description of the problem.

This plugin was rendered obsolete when a fix for WordPress Ticket #2603 became available in WordPress 2.2.

The CRCRLF plugin is named after the signature damage done to the email sent – each line suffices with two carriage return (CR) characters followed by a linefeed (LF) character.

Installation Instructions

Recommendation: Don’t follow these instructions, if you can update WordPress to the latest instead!

  • Download CRCRLF 1.0.
  • Unzip it and copy it into the plugins directory on your WordPress server.
  • Activate it in the Admin Plugins page.
  • You’re done!


Server Environment

If your server is Unix, then you need the plugin, it works, and it is tested.

If your server is Windows, then you don’t need the plugin, it should work and it is not tested.

If your server is Mac OS, then you might need the plugin, it should work and it is not tested.

Client Environment

The plugin was tested against Microsoft Outlook 2003 SP2 running on Windows.

WordPress version

If your WordPress version is 2.2.x, then you don’t need the plugin, it does no harm, and it is tested.

If your WordPress version is 2.0.x or 2.1.x, then you need the plugin, it works, and it is tested.

More accurately, it has been tested on WP 2.0.1, 2.0.2, 2.0.3, 2.0.4, 2.0.5, 2.0.6, 2.1.1 and 2.1.2.

If your WordPress version is between 1.5 and 2.0, then you need the plugin, it should work, but it is not tested.

If your WordPress version is less than 1.5, then you probably need the plugin, it probably won’t work, and it is not tested.

Other Plugins

This plugin redefines a pluggable function called wp_mail. There are other plugins that also overwrite that function. This plugin may be rendered inoperative if other such plugins are activated and/or vice versa.

Version History

  • 1.0, 29-Mar-06, CRLFLF goes live
  • -.-, 24-Jun-07, CRLFLF is confirmed as obsolete.


  1. Hey,

    So does wordpress 1.5.2 suffer from this bug?

    Just wondering,


  2. Will,

    Short answer: Yes.

    Longer Answer:

    The bug is definitely present from WordPress 1.5 to 2.0.2. It was probably present before that, but I can’t confirm. I suspect it will still be present for a while, because it is low in priority for most users.

    I see no reason why the CRCRLF plugin wouldn’t work for all WordPress versions 1.5+ (including 1.5.2) but it has not been tested on anything before WP 2.0.2. If you try it on 1.5.2 and it works, please let me know.

    It was a good question; thank you. I have updated the page to reflect this.

  3. Thanks so much for this. I was going crazy because amavisd-new was rejecting all mail from WordPress:

    550 5.7.1 Rejected, id=20204-08 – BAD_HEADER: Non-encoded 8-bit data (char E2 hex)

    Now everything seems fine.

  4. Nazgul has published a patch for WordPress to address this problem. Hopefully, it will be included in WordPress 2.1.

    Kudos to Nazgul.

  5. So Julian, does this mean I can safely delete the plugin now, or is it not rolled with the code yet? I’m on 2.0.5, but there’s nothing mentioned about this version.

  6. Jonathan,

    The patch is not yet rolled in with the code, so it is premature to deactivate the plugin.

    Not only isn’t it part of WordPress 2.0.5, but by the looks of the recent change to the ticket, it won’t be part of WordPress 2.0.6 or 2.1. It is now targetted for 2.2.

  7. I was just going to ask the same thing i am doing a list of all plugins that are updated for 2.1 for my Google Blog and it is not many. My favorite Adsense Delux does not work 🙁

  8. I can confirm that CRCRLF is both required, and works, for WP 2.1.1.

  9. Your download link results in a file containing version 0.9 Beta of your plugin… I’ll just ignore the version info and test it anyway 😉

  10. Ravan,

    Boy, am I red-faced! The wrong version has been available for almost 12 months, and you’re the first to point it out. I feel like I have had a piece of broccoli stuck in my teeth for the whole evening!

    Now corrected.

    The good news is that the 0.9 Beta version was the final “Release Candidate”. That means the only difference between it and Version 1.0 is the version number!

    So feel free to keep using 0.9 Beta; it should still work fine.

  11. You’re welcome 🙂

    But there is another little piece of broccoli: The plugin link truns out to be not valid anymore so http://www.somethinkodd.com/WordPress-Email-CR-LF-Fix points to a non-existent page… So if your traffic has been dropping, maybe that’s why 😉

    Anyway, I can confirm that your plugin is wroking like a charm on my WP 2.1.2 and corrects the double empty lines in e-mail send by the Subscribe2 plugin (that suprisingly is working fine still on the latest WP version)

    Thank you for this great fix!

  12. Thanks again, Ravan. That is now fixed (at my end – no need for the users to do anything.)

  13. WordPress 2.2 now uses PHPMailer.

    That’s exciting news. PHPMailer probably solves the linefeed problem, and will make this plugin obsolete.

    The defect that CRLFLF was written to overcome has been closed on the WordPress site

    I haven’t tested it yet.

  14. I have updated the CRLFLF page, above, to confirm that the plugin is now obsolete.

    If you update your WordPress installation to 2.2 or above, you do not need the plugin.

    On WordPress 2.2.0 and 2.2.1, the plugin doesn’t seem to cause any harm, which is good, but you may as well deactivate it and delete the file crlflf.php in case it causes any problems in future releases.

    The plugin will remain live here, for a while, to assist people who cannot yet upgrade their WordPress installations to 2.2.

    I won’t be doing any more development on this plugin.

    I hope you found it as useful as I did.

  15. The necessary plugin 🙂
    It is established easily and perfectly works.
    Thank u so much!

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Web Mentions

  1. Blogging Pro China » Blog Archive » WordPress Plugin: CRCRLF

  2. Crcrlf - DevelopeNet.com

  3. WP Plugins DB » Blog Archive » CRCRLF