This plugin hasn’t been tested with the latest 3 major releases of WordPress. It may no longer be maintained or supported and may have compatibility issues when used with more recent versions of WordPress.

WP Opt-in


This plugin can be used to send e-mail to users. The front side of the ‘WP Opt-in’ plugin is a simple form with an e-mail input field and a submit button. By entering an e-mail address into the field and pressing submit, an e-mail is sent automatically to the specified address.

The contents and sender of the automatic e-mail can be specified in options, along with whatever you would like for status messages and other text for the front side.

IP address and time for submit is stored together with the e-mail address in the database. E-mail entries in the database can be selectively deleted. Export to a Bcc friendly format is also possible.


Visit the plugin home page.


  1. Deactivate the plugin in the WordPress ‘Plugins’ menu if you are upgrading
  2. Download and unzip the plugin
  3. Upload the wp-opt-in folder to the /wp-content/plugins/ folder
  4. Active the plugin, place the widget in your sidebar and edit its title by using the ‘Presentation’ menu
  5. Configure the plugin in the ‘WP Opt-in’ menu located under the WordPress ‘Options’ menu

If your theme does not support widgets, you can paste <?php if (function_exists('wpoi_opt_in')) { wpoi_opt_in(); } ?> into your sidebar file. This file may be called ‘sidebar.php’ or similar.


Can I send e-mail to all users who have asked for information through this plugin?

Yes. Simply copy all the e-mail addresses from the ‘Bcc friendly format’ section on the plugin options page. Paste them into the Bcc field in your favorite e-mail client software.

No e-mails are sent! Why?

Check if PHP is configured to use a working SMTP server, possibly in a file called php.ini.

What does Bcc mean?

Blind carbon copy. A receipient field for e-mail. Using it results in not revealing e-mail addresses between the recipients.

Why do the plugin mess up my theme when including it in the sidebar?

The options might be messed up. Try the default options:

  • Bad e-mail: <p><b>Bad e-mail address.</b></p>
  • Failed to send: <p><b>Failed sending to e-mail address.</b></p>
  • Success: <p><b>Sent requested e-mail.</b></p>
  • Form header: <div id="wpoi_form">Receive information automagically here.
  • Form footer: </div>
  • E-mail field: E-mail:
  • Submit button: Submit
Can spammers use this to get me in trouble?

Subject, sender and contents of the e-mail sent from this plugin is controlled by the plugin and you. There should be no reason for sending someone this information unless they asked for it.

What about security?

The input e-mail address is checked for suspicious characters before it’s used.


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Contributors & Developers

“WP Opt-in” is open source software. The following people have contributed to this plugin.


Translate “WP Opt-in” into your language.

Interested in development?

Browse the code, check out the SVN repository, or subscribe to the development log by RSS.



  • Fixed init action used for the redirect option.


  • Modified default options for form header for better CSS.
  • Added description to more of the options.
  • Redirect option to enable possibility for a opt-in success page.


  • Fixed support for empty options. Thanks to GirlsCanCode.


  • Try to fix double e-mail to self.
  • Remove unnecessary code in opt-in-form


  • Text in notification e-mail changed to be more general.
  • Made it possible to place the php file in either a wp-opt-in folder or the plugins folder. Recommended: folder (to be compatible with future versions).


  • Better Windows/Linux support. Thanks to Last Programmer for testing.


  • Improved PHP mail() compatibility


  • Option to send notification email
  • Use form footer field
  • Seamlessly perform database upgrade.


  • Correct bugfix in 0.9.1.


  • Tiny bugfix.


  • Remove old duplicates of submitted new email.


  • Fix register activation hook. Thanks to Jared.


  • Create initial opt-in-users database table fix.


  • Fix widgets on more WordPress versions.


  • Add control to edit widget title.


  • Correct typos introduced in 0.3.


  • Widget support. Thanks to Rune.


  • Add a comment and improve readme.


  • Initial version