函数文档

wp_mail()

💡 云策文档标注

概述

wp_mail() 是 WordPress 中用于发送电子邮件的核心函数,类似于 PHP 的 mail() 函数。它支持设置收件人、主题、消息内容、自定义头部、附件和嵌入文件,并可通过多个过滤器进行自定义配置。

关键要点

  • 函数返回布尔值表示邮件是否成功发送,但成功发送不保证收件人实际收到邮件。
  • 默认内容类型为 text/plain,不支持 HTML;可通过 'wp_mail_content_type' 过滤器或设置 Content-Type 头部来发送 HTML 邮件。
  • 默认字符集基于博客设置,可通过 'wp_mail_charset' 过滤器修改。
  • 支持通过 $headers 参数设置 From、Cc、Bcc 等头部,建议使用数组格式以避免格式错误。
  • 附件和嵌入文件需提供文件系统路径,嵌入文件可通过 cid: URL 在 HTML 中引用。
  • 函数依赖于 PHP 的 mail() 函数或 PHPMailer,需确保服务器 SMTP 配置正确。
  • 提供多个钩子如 'wp_mail'、'pre_wp_mail'、'phpmailer_init' 等,允许在发送前后进行干预和自定义。

代码示例

// 基本用法示例
$to = 'sendto@example.com';
$subject = 'The subject';
$body = 'The email body content';
$headers = array('Content-Type: text/html; charset=UTF-8');

wp_mail( $to, $subject, $body, $headers );

注意事项

  • 发送 HTML 邮件后,建议重置 'wp_mail_content_type' 过滤器为 'text/plain',以避免影响其他邮件发送。
  • 邮件地址需符合 RFC 2822 标准,可接受数组或逗号分隔的列表格式。
  • 函数在 'plugins_loaded' 钩子后可用,确保在适当时机调用。
  • 某些服务器可能要求存在 wordpress@domain.com 邮箱账户才能正常发送邮件。

📄 原文内容

Sends an email, similar to PHP’s mail function.

Description

A true return value does not automatically mean that the user received the email successfully. It just only means that the method used was able to process the request without any errors.

The default content type is text/plain which does not allow using HTML.
However, you can set the content type of the email by using the ‘wp_mail_content_type’ filter.

The default charset is based on the charset used on the blog. The charset can be set using the ‘wp_mail_charset’ filter.

When using the $embeds parameter to embed images for use in HTML emails, reference the embedded file in your HTML with a cid: URL whose value matches the file’s Content-ID. By default, the Content-ID (cid) used for each embedded file is the key in the embeds array, unless modified via the ‘wp_mail_embed_args’ filter. For example:

<img src="cid:0" alt="Logo"> <img src="cid:my-image" alt="Image">

You may also customize the Content-ID for each file by using the ‘wp_mail_embed_args’ filter and setting the cid value.

Parameters

$tostring|string[]required
Array or comma-separated list of email addresses to send message.
$subjectstringrequired
Email subject.
$messagestringrequired
Message contents.
$headersstring|string[]optional
Additional headers.
$attachmentsstring|string[]optional
Paths to files to attach.

Default:array()

$embedsstring|string[]optional
Paths to files to embed.

Default:array()

Return

bool Whether the email was sent successfully.

More Information

Usage

wp_mail( $to, $subject, $message, $headers, $attachments );

Optional filters ‘wp_mail_from‘ and ‘wp_mail_from_name‘ are run on the sender email address and name. The return values are reassembled into a ‘from’ address like ‘”Example User” ‘ If only ‘wp_mail_from‘ returns a value, then just the email address will be used with no name.

The default content type is ‘text/plain’ which does not allow using HTML. You can set the content type of the email either by using the ‘wp_mail_content_type‘ filter ( see example below), or by including a header like “Content-type: text/html”. Be careful to reset ‘wp_mail_content_type’ back to ‘text/plain’ after you send your message, though, because failing to do so could lead to unexpected problems with e-mails from WP or plugins/themes.

The default charset is based on the charset used on the blog. The charset can be set using the ‘wp_mail_charset‘ filter.

Notes

  • A true return value does not automatically mean that the user received the email successfully.
  • For this function to work, the settings SMTP and smtp_port (default: 25) need to be set in your php.ini file.
  • The function is available after the hook 'plugins_loaded'.
  • The filenames in the $attachments attribute have to be filesystem paths.

Valid Address Formats

All email addresses supplied to wp_mail() as the $to parameter must comply with RFC 2822. Some valid examples:

  • user@example.com
  • user@example.com, anotheruser@example.com
  • User
  • User , Another User

The same applies to Cc: and Bcc: fields in $headers, but as noted in the next section, it’s better to push multiple addresses into an array instead of listing them on a single line. Either address format, with or without the user name, may be used.

Using $headers To Set “From:”, “Cc:” and “Bcc:” Parameters

To set the “From:” email address to something other than the WordPress default sender, or to add “Cc:” and/or “Bcc:” recipients, you must use the $headers argument.

$headers can be a string or an array, but it may be easiest to use in the array form. To use it, push a string onto the array, starting with “From:”, “Bcc:” or “Cc:” (note the use of the “:”), followed by a valid email address.

When you are using the array form, you do not need to supply line breaks ("n" or "rn"). Although the function can handle multiple emails per line, it may simply be easier to push each email address separately onto the $headers array. The function will figure it out and will build the proper Mime header automagically. Just don’t forget that each string you push must have the header type as the first part of the string (“From:”, “Cc:” or “Bcc:”)

Source

function wp_mail( $to, $subject, $message, $headers = '', $attachments = array(), $embeds = array() ) {
	// Compact the input, apply the filters, and extract them back out.

	/**
	 * Filters the wp_mail() arguments.
	 *
	 * @since 2.2.0
	 *
	 * @param array $args {
	 *     Array of the `wp_mail()` arguments.
	 *
	 *     @type string|string[] $to          Array or comma-separated list of email addresses to send message.
	 *     @type string          $subject     Email subject.
	 *     @type string          $message     Message contents.
	 *     @type string|string[] $headers     Additional headers.
	 *     @type string|string[] $attachments Paths to files to attach.
	 *     @type string|string[] $embeds      Paths to files to embed.
	 * }
	 */
	$atts = apply_filters( 'wp_mail', compact( 'to', 'subject', 'message', 'headers', 'attachments', 'embeds' ) );

	/**
	 * Filters whether to preempt sending an email.
	 *
	 * Returning a non-null value will short-circuit <a href="https://developer.wordpress.org/reference/functions/wp_mail/">wp_mail()</a>, returning
	 * that value instead. A boolean return value should be used to indicate whether
	 * the email was successfully sent.
	 *
	 * @since 5.7.0
	 *
	 * @param null|bool $return Short-circuit return value.
	 * @param array     $atts {
	 *     Array of the `wp_mail()` arguments.
	 *
	 *     @type string|string[] $to          Array or comma-separated list of email addresses to send message.
	 *     @type string          $subject     Email subject.
	 *     @type string          $message     Message contents.
	 *     @type string|string[] $headers     Additional headers.
	 *     @type string|string[] $attachments Paths to files to attach.
	 *     @type string|string[] $embeds      Paths to files to embed.
	 * }
	 */
	$pre_wp_mail = apply_filters( 'pre_wp_mail', null, $atts );

	if ( null !== $pre_wp_mail ) {
		return $pre_wp_mail;
	}

	if ( isset( $atts['to'] ) ) {
		$to = $atts['to'];
	}

	if ( ! is_array( $to ) ) {
		$to = explode( ',', $to );
	}

	if ( isset( $atts['subject'] ) ) {
		$subject = $atts['subject'];
	}

	if ( isset( $atts['message'] ) ) {
		$message = $atts['message'];
	}

	if ( isset( $atts['headers'] ) ) {
		$headers = $atts['headers'];
	}

	if ( isset( $atts['attachments'] ) ) {
		$attachments = $atts['attachments'];
	}

	if ( ! is_array( $attachments ) ) {
		$attachments = explode( "n", str_replace( "rn", "n", $attachments ) );
	}

	if ( isset( $atts['embeds'] ) ) {
		$embeds = $atts['embeds'];
	}

	if ( ! is_array( $embeds ) ) {
		$embeds = explode( "n", str_replace( "rn", "n", $embeds ) );
	}

	global $phpmailer;

	// (Re)create it, if it's gone missing.
	if ( ! ( $phpmailer instanceof PHPMailerPHPMailerPHPMailer ) ) {
		require_once ABSPATH . WPINC . '/PHPMailer/PHPMailer.php';
		require_once ABSPATH . WPINC . '/PHPMailer/SMTP.php';
		require_once ABSPATH . WPINC . '/PHPMailer/Exception.php';
		require_once ABSPATH . WPINC . '/class-wp-phpmailer.php';
		$phpmailer = new WP_PHPMailer( true );

		$phpmailer::$validator = static function ( $email ) {
			return (bool) is_email( $email );
		};
	}

	// Headers.
	$cc       = array();
	$bcc      = array();
	$reply_to = array();

	if ( empty( $headers ) ) {
		$headers = array();
	} else {
		if ( ! is_array( $headers ) ) {
			/*
			 * Explode the headers out, so this function can take
			 * both string headers and an array of headers.
			 */
			$tempheaders = explode( "n", str_replace( "rn", "n", $headers ) );
		} else {
			$tempheaders = $headers;
		}
		$headers = array();

		// If it's actually got contents.
		if ( ! empty( $tempheaders ) ) {
			// Iterate through the raw headers.
			foreach ( (array) $tempheaders as $header ) {
				if ( ! str_contains( $header, ':' ) ) {
					if ( false !== stripos( $header, 'boundary=' ) ) {
						$parts    = preg_split( '/boundary=/i', trim( $header ) );
						$boundary = trim( str_replace( array( "'", '"' ), '', $parts[1] ) );
					}
					continue;
				}
				// Explode them out.
				list( $name, $content ) = explode( ':', trim( $header ), 2 );

				// Cleanup crew.
				$name    = trim( $name );
				$content = trim( $content );

				switch ( strtolower( $name ) ) {
					// Mainly for legacy -- process a "From:" header if it's there.
					case 'from':
						$bracket_pos = strpos( $content, '<' );
						if ( false !== $bracket_pos ) {
							// Text before the bracketed email is the "From" name.
							if ( $bracket_pos > 0 ) {
								$from_name = substr( $content, 0, $bracket_pos );
								$from_name = str_replace( '"', '', $from_name );
								$from_name = trim( $from_name );
							}

							$from_email = substr( $content, $bracket_pos + 1 );
							$from_email = str_replace( '>', '', $from_email );
							$from_email = trim( $from_email );

							// Avoid setting an empty $from_email.
						} elseif ( '' !== trim( $content ) ) {
							$from_email = trim( $content );
						}
						break;
					case 'content-type':
						if ( str_contains( $content, ';' ) ) {
							list( $type, $charset_content ) = explode( ';', $content );
							$content_type                   = trim( $type );
							if ( false !== stripos( $charset_content, 'charset=' ) ) {
								$charset = trim( str_replace( array( 'charset=', '"' ), '', $charset_content ) );
							} elseif ( false !== stripos( $charset_content, 'boundary=' ) ) {
								$boundary = trim( str_replace( array( 'BOUNDARY=', 'boundary=', '"' ), '', $charset_content ) );
								$charset  = '';
								if ( preg_match( '~^multipart/(S+)~', $content_type, $matches ) ) {
									$content_type = 'multipart/' . strtolower( $matches[1] ) . '; boundary="' . $boundary . '"';
								}
							}

							// Avoid setting an empty $content_type.
						} elseif ( '' !== trim( $content ) ) {
							$content_type = trim( $content );
						}
						break;
					case 'cc':
						$cc = array_merge( (array) $cc, explode( ',', $content ) );
						break;
					case 'bcc':
						$bcc = array_merge( (array) $bcc, explode( ',', $content ) );
						break;
					case 'reply-to':
						$reply_to = array_merge( (array) $reply_to, explode( ',', $content ) );
						break;
					default:
						// Add it to our grand headers array.
						$headers[ trim( $name ) ] = trim( $content );
						break;
				}
			}
		}
	}

	// Empty out the values that may be set.
	$phpmailer->clearAllRecipients();
	$phpmailer->clearAttachments();
	$phpmailer->clearCustomHeaders();
	$phpmailer->clearReplyTos();
	$phpmailer->Body    = '';
	$phpmailer->AltBody = '';

	/*
	 * Reset encoding to 8-bit, as it may have been automatically downgraded
	 * to 7-bit by PHPMailer (based on the body contents) in a previous call
	 * to wp_mail().
	 *
	 * See https://core.trac.wordpress.org/ticket/33972
	 */
	$phpmailer->Encoding = PHPMailerPHPMailerPHPMailer::ENCODING_8BIT;

	// Set "From" name and email.

	// If we don't have a name from the input headers.
	if ( ! isset( $from_name ) ) {
		$from_name = 'WordPress';
	}

	/*
	 * If we don't have an email from the input headers, default to wordpress@$sitename
	 * Some hosts will block outgoing mail from this address if it doesn't exist,
	 * but there's no easy alternative. Defaulting to admin_email might appear to be
	 * another option, but some hosts may refuse to relay mail from an unknown domain.
	 * See https://core.trac.wordpress.org/ticket/5007.
	 */
	if ( ! isset( $from_email ) ) {
		// Get the site domain and get rid of www.
		$sitename   = wp_parse_url( network_home_url(), PHP_URL_HOST );
		$from_email = 'wordpress@';

		if ( null !== $sitename ) {
			if ( str_starts_with( $sitename, 'www.' ) ) {
				$sitename = substr( $sitename, 4 );
			}

			$from_email .= $sitename;
		}
	}

	/**
	 * Filters the email address to send from.
	 *
	 * @since 2.2.0
	 *
	 * @param string $from_email Email address to send from.
	 */
	$from_email = apply_filters( 'wp_mail_from', $from_email );

	/**
	 * Filters the name to associate with the "from" email address.
	 *
	 * @since 2.3.0
	 *
	 * @param string $from_name Name associated with the "from" email address.
	 */
	$from_name = apply_filters( 'wp_mail_from_name', $from_name );

	try {
		$phpmailer->setFrom( $from_email, $from_name, false );
	} catch ( PHPMailerPHPMailerException $e ) {
		$mail_error_data                             = compact( 'to', 'subject', 'message', 'headers', 'attachments' );
		$mail_error_data['phpmailer_exception_code'] = $e->getCode();

		/** This filter is documented in wp-includes/pluggable.php */
		do_action( 'wp_mail_failed', new WP_Error( 'wp_mail_failed', $e->getMessage(), $mail_error_data ) );

		return false;
	}

	// Set mail's subject and body.
	$phpmailer->Subject = $subject;
	$phpmailer->Body    = $message;

	// Set destination addresses, using appropriate methods for handling addresses.
	$address_headers = compact( 'to', 'cc', 'bcc', 'reply_to' );

	foreach ( $address_headers as $address_header => $addresses ) {
		if ( empty( $addresses ) ) {
			continue;
		}

		foreach ( (array) $addresses as $address ) {
			try {
				// Break $recipient into name and address parts if in the format "Foo <bar@baz.com>".
				$recipient_name = '';

				if ( preg_match( '/(.*)<(.+)>/', $address, $matches ) ) {
					if ( count( $matches ) === 3 ) {
						$recipient_name = $matches[1];
						$address        = $matches[2];
					}
				}

				switch ( $address_header ) {
					case 'to':
						$phpmailer->addAddress( $address, $recipient_name );
						break;
					case 'cc':
						$phpmailer->addCC( $address, $recipient_name );
						break;
					case 'bcc':
						$phpmailer->addBCC( $address, $recipient_name );
						break;
					case 'reply_to':
						$phpmailer->addReplyTo( $address, $recipient_name );
						break;
				}
			} catch ( PHPMailerPHPMailerException $e ) {
				continue;
			}
		}
	}

	// Set to use PHP's mail().
	$phpmailer->isMail();

	// Set Content-Type and charset.

	// If we don't have a Content-Type from the input headers.
	if ( ! isset( $content_type ) ) {
		$content_type = 'text/plain';
	}

	/**
	 * Filters the wp_mail() content type.
	 *
	 * @since 2.3.0
	 *
	 * @param string $content_type Default wp_mail() content type.
	 */
	$content_type = apply_filters( 'wp_mail_content_type', $content_type );

	$phpmailer->ContentType = $content_type;

	// Set whether it's plaintext, depending on $content_type.
	if ( 'text/html' === $content_type ) {
		$phpmailer->isHTML( true );
	}

	// If we don't have a charset from the input headers.
	if ( ! isset( $charset ) ) {
		$charset = get_bloginfo( 'charset' );
	}

	/**
	 * Filters the default wp_mail() charset.
	 *
	 * @since 2.3.0
	 *
	 * @param string $charset Default email charset.
	 */
	$phpmailer->CharSet = apply_filters( 'wp_mail_charset', $charset );

	// Set custom headers.
	if ( ! empty( $headers ) ) {
		foreach ( (array) $headers as $name => $content ) {
			// Only add custom headers not added automatically by PHPMailer.
			if ( ! in_array( $name, array( 'MIME-Version', 'X-Mailer' ), true ) ) {
				try {
					$phpmailer->addCustomHeader( sprintf( '%1$s: %2$s', $name, $content ) );
				} catch ( PHPMailerPHPMailerException $e ) {
					continue;
				}
			}
		}
	}

	if ( ! empty( $attachments ) ) {
		foreach ( $attachments as $filename => $attachment ) {
			$filename = is_string( $filename ) ? $filename : '';

			try {
				$phpmailer->addAttachment( $attachment, $filename );
			} catch ( PHPMailerPHPMailerException $e ) {
				continue;
			}
		}
	}

	if ( ! empty( $embeds ) ) {
		foreach ( $embeds as $key => $embed_path ) {
			/**
			 * Filters the arguments for PHPMailer's addEmbeddedImage() method.
			 *
			 * @since 6.9.0
			 *
			 * @param array $args {
			 *     An array of arguments for `addEmbeddedImage()`.
			 *     @type string $path        The path to the file.
			 *     @type string $cid         The Content-ID of the image. Default: The key in the embeds array.
			 *     @type string $name        The filename of the image.
			 *     @type string $encoding    The encoding of the image. Default: 'base64'.
			 *     @type string $type        The MIME type of the image. Default: empty string, which lets PHPMailer auto-detect.
			 *     @type string $disposition The disposition of the image. Default: 'inline'.
			 * }
			 */
			$embed_args = apply_filters(
				'wp_mail_embed_args',
				array(
					'path'        => $embed_path,
					'cid'         => (string) $key,
					'name'        => basename( $embed_path ),
					'encoding'    => 'base64',
					'type'        => '',
					'disposition' => 'inline',
				)
			);

			try {
				$phpmailer->addEmbeddedImage(
					$embed_args['path'],
					$embed_args['cid'],
					$embed_args['name'],
					$embed_args['encoding'],
					$embed_args['type'],
					$embed_args['disposition']
				);
			} catch ( PHPMailerPHPMailerException $e ) {
				continue;
			}
		}
	}

	/**
	 * Fires after PHPMailer is initialized.
	 *
	 * @since 2.2.0
	 *
	 * @param PHPMailer $phpmailer The PHPMailer instance (passed by reference).
	 */
	do_action_ref_array( 'phpmailer_init', array( &$phpmailer ) );

	$mail_data = compact( 'to', 'subject', 'message', 'headers', 'attachments', 'embeds' );

	// Send!
	try {
		$send = $phpmailer->send();

		/**
		 * Fires after PHPMailer has successfully sent an email.
		 *
		 * The firing of this action does not necessarily mean that the recipient(s) received the
		 * email successfully. It only means that the `send` method above was able to
		 * process the request without any errors.
		 *
		 * @since 5.9.0
		 *
		 * @param array $mail_data {
		 *     An array containing the email recipient(s), subject, message, headers, and attachments.
		 *
		 *     @type string[] $to          Email addresses to send message.
		 *     @type string   $subject     Email subject.
		 *     @type string   $message     Message contents.
		 *     @type string[] $headers     Additional headers.
		 *     @type string[] $attachments Paths to files to attach.
		 *     @type string[] $embeds      Paths to files to embed.
		 * }
		 */
		do_action( 'wp_mail_succeeded', $mail_data );

		return $send;
	} catch ( PHPMailerPHPMailerException $e ) {
		$mail_data['phpmailer_exception_code'] = $e->getCode();

		/**
		 * Fires after a PHPMailerPHPMailerException is caught.
		 *
		 * @since 4.4.0
		 *
		 * @param WP_Error $error A WP_Error object with the PHPMailerPHPMailerException message, and an array
		 *                        containing the mail recipient, subject, message, headers, and attachments.
		 */
		do_action( 'wp_mail_failed', new WP_Error( 'wp_mail_failed', $e->getMessage(), $mail_data ) );

		return false;
	}
}

Hooks

do_action_ref_array( ‘phpmailer_init’, PHPMailer $phpmailer )

Fires after PHPMailer is initialized.

apply_filters( ‘pre_wp_mail’, null|bool $return, array $atts )

Filters whether to preempt sending an email.

apply_filters( ‘wp_mail’, array $args )

Filters the wp_mail() arguments.

apply_filters( ‘wp_mail_charset’, string $charset )

Filters the default wp_mail() charset.

apply_filters( ‘wp_mail_content_type’, string $content_type )

Filters the wp_mail() content type.

apply_filters( ‘wp_mail_embed_args’, array $args )

Filters the arguments for PHPMailer’s addEmbeddedImage() method.

do_action( ‘wp_mail_failed’, WP_Error $error )

Fires after a PHPMailerPHPMailerException is caught.

apply_filters( ‘wp_mail_from’, string $from_email )

Filters the email address to send from.

apply_filters( ‘wp_mail_from_name’, string $from_name )

Filters the name to associate with the “from” email address.

do_action( ‘wp_mail_succeeded’, array $mail_data )

Fires after PHPMailer has successfully sent an email.

Changelog

Version Description
6.9.0 Improved Content-Type header handling for multipart messages.
5.5.0 is_email() is used for email validation, instead of PHPMailer’s default validator.
1.2.1 Introduced.

User Contributed Notes

  1. Skip to note 18 content

    To send HTML formatted mail, you also can specify the Content-Type HTTP header in the $headers parameter:

    $to = 'sendto@example.com';
    $subject = 'The subject';
    $body = 'The email body content';
    $headers = array('Content-Type: text/html; charset=UTF-8');
    
    wp_mail( $to, $subject, $body, $headers );

  2. Skip to note 19 content

    Example using the array form of $headers:

    ';
    $headers[] = 'Cc: John Q Codex <jqc@wordpress.org>';
    $headers[] = 'Cc: <a href="mailto:iluvwp@wordpress.org">iluvwp@wordpress.org</a>'; // note you can just use a simple email address
    
    wp_mail( $to, $subject, $message, $headers );
    ?>

  3. Skip to note 20 content

    Here’s an example of a basic configuration for SMTP (so phpmailer will be used instead of php’s mail()):

    add_action( 'phpmailer_init', 'mailer_config', 10, 1);
    function mailer_config(PHPMailer $mailer){
      $mailer->IsSMTP();
      $mailer->Host = "mail.telemar.it"; // your SMTP server
      $mailer->Port = 25;
      $mailer->SMTPDebug = 2; // write 0 if you don't want to see client/server communication in page
      $mailer->CharSet  = "utf-8";
    }

    Here’s an example of a basic error logging:

    add_action('wp_mail_failed', 'log_mailer_errors', 10, 1);
    function log_mailer_errors( $wp_error ){
      $fn = ABSPATH . '/mail.log'; // say you've got a mail.log file in your server root
      $fp = fopen($fn, 'a');
      fputs($fp, "Mailer Error: " . $wp_error->get_error_message() ."n");
      fclose($fp);
    }

    Then use wp_mail() to send your mail.

    If you’re using it for sending a form and your form’s action is the page’s permalink, you can do some basic checking for $_POST lenght/count to see if the page comes from a form submission.

    if(count($_POST) != 0){ // on top of page
      // Then collect form data and try to send the form and write messages and so on...
      // Note: set $mailer->SMTPDebug to 0 to prevent it to write server messages on the page
    }

    NOTE: if you are using MAMP PRO to test from your local server, you should:

    – go to the Postfix panel
    – write your current virtual server as the ‘domain of outgoing email’
    – activate ‘use a smart host for routing’
    – write your provider’s smtp server (the same you are using in your mail client config)
    – Eventually add authentication (then you should also setup the credentials in the phpmailer_init action)

  4. Skip to note 21 content

    Having spent nearly a day banging my head against this one, I would strongly recommend that the doc for wp_mail() include the tip that many servers will require that a mail user account be created with the email address of wordpress@domain.com before this function will work. I would have NEVER figured that one out without many hours of google searches.

  5. Skip to note 22 content

    Combining Content-Type(HTML) and From (Site name and “from” email)

    $to = 'emailsendto@example.com';
    $subject = 'The subject';
    $body = 'The email body content';
    $headers = array('Content-Type: text/html; charset=UTF-8','From: My Site Name <support@example.com>');
    
    wp_mail( $to, $subject, $body, $headers );

  6. Skip to note 23 content

    Switch to HTML formatted email (using the <a href="https://developer.wordpress.org/reference/hooks/wp_mail_content_type/" rel="nofollow">wp_mail_content_type</a> filter):

    https://core.trac.wordpress.org/ticket/23578</a>
    remove_filter( 'wp_mail_content_type', 'wpdocs_set_html_mail_content_type' );
    
    function wpdocs_set_html_mail_content_type() {
    	return 'text/html';
    }
    ?>

  7. Skip to note 24 content

    If you need to set the Reply-To address, note that the syntax which PHPMailer needs is pretty specific. The email address must be enclosed within <> characters. It’s also advisable to set the “reply to” name.

    $headers = array(
      'Reply-To: Person Name <person.name@example.com>',
    );

  8. Skip to note 28 content

    To send e-mail to admin:

    $to = get_option( 'admin_email' );
    $subject = 'The subject';
    $body = 'The email body content';
    $headers = array( 'Content-Type: text/html; charset=UTF-8' );
    wp_mail( $to, $subject, $message, $headers, array( '' ) );

  9. Skip to note 29 content

    As of 4.6 header from can’t be a post variable, need to be set before otherwise your site will show php error “Fatal error: Uncaught exception ‘phpmailerException’ with message ‘Invalid address: (setFrom)”

    This is due to ‘from email’ being set as variable and is not yet being passed by form submit.

    $headers = "From: $name <$email>" . "rn";

    Fix by predefining a variable for both $name and $email that will be overwritten after submit(ex.1), or set hardcoded(ex.2).
    ex.1

    $name = "Site name";
    $email = "info@sitename.com";
    if(isset $_POST["name"]){
    $name = sanitize_text_field($_POST["name"]);
    $email = sanitize_email($_POST["email"]);
    }

    ex.2

    $headers = "From: Site name <info@sitename.com>" . "rn";

  10. Skip to note 30 content

    It’s important to know that this function might fail if you specify an empty body, even if using a SMTP.

    wp_mail( 'email@provider.com', 'Subject', '' ); // returns false, the email was not sent
    wp_mail( 'email@provider.com', 'Subject', 'Body' ); // returns true (if everything else is working)