WP HTML Mail Documentation

No, this is not a newsletter tool, it just makes your emails beautiful but doesn’t send custom ones.

Go to your Contact Form 7 email settings and change email type from HTML to text. WP HTML Mail will take care of the HTML.

There’s a filter to change the header HTML code. Just add this to your (child-)themes functions.php:

add_filter('haet_mail_header', function( $header ){
  return 'hello <strong>world</strong>';
});

Of course you can display HTML code, not just text.

By default the logo or header image links to your website. If you want to remove this link add the following line of code to your themes functions.php

add_filter( 'haet_mail_link_header', '__return_false' );

There’s a filter to change the footer HTML code. Just add this to your (child-)themes functions.php:

add_filter('haet_mail_footer', function( $header ){
    return 'hello <strong>world</strong>';
});

You can add your own CSS code for desktop and mobile. Just add this example to your (child-)themes functions.php and customize it:

add_filter( 'haet_mail_css_desktop', function( $css ){
    $css.= ' h1{ border-bottom: 2px solid green; } ';
    return $css;
});

add_filter( 'haet_mail_css_mobile', function( $css ){
    $css .= ' h1{ background:red; } ';
    return $css;
});

Another example of custom CSS, but not all email clients support rounded corners. In most versions of Microsoft Outlook you will only see regular border with edges.

add_filter( 'haet_mail_css_desktop', function( $css ){
    $css .= '  
            td.header{
            	border: 1px solid #ddd;
            	border-bottom: none;
            	border-top-left-radius: 10px;
            	border-top-right-radius: 10px;
            }
            td.content{
            	border: 1px solid #ddd;
            	border-top: none;
            	border-bottom: none
            }
            td.footer-text{
            	border: 1px solid #ddd;
            	border-top: none;
            	border-bottom-left-radius: 10px;
            	border-bottom-right-radius: 10px;
            }
        ';
    return $css;
});

Add the following lines of code to your themes functions.php

add_filter( 'haet_mail_preheader', function( $pre_header, $email ){
  return 'this is my custom preheader';
}, 10, 2 );

If you want to remove the pre-header:

add_filter('haet_mail_preheader','__return_empty_string');

Find anything all emails hav in common. It may be the sender, a word in the subject or something in the email body.
Then add this function to your (child-)themes functions.php and customize it. Return TRUE if the template should be used and FALSE if not.

// return true if you want to use a template for current mail
// return false if you want to leave the content of this email unchanged
add_filter( 'haet_mail_use_template',
  function ( $use_template, $mail ){
  // $mail['to'] ...
  // $mail['subject'] ...
  // $mail['message'] ...
  // $mail['headers'] ...
  // $mail['attachments'] ...
  return true;
}, 10, 2 );

In detail: Let’s assume all emails from plugin X contain the word “foo” in subject:

add_filter( 'haet_mail_use_template', 
  function ( $use_template, $mail ){ 
    // find the string "foo" in subject
    if( stripos( $mail['subject'], 'foo' ) !== false )
      return false;
    
    // otherwise do not change
    return $use_template;
  }
  , 10, 2 
);