function _wp_privacy_send_erasure_fulfillment_notification( $request_id ) {
	$request = wp_get_user_request_data( $request_id );

	if ( ! is_a( $request, 'WP_User_Request' ) || 'request-completed' !== $request->status ) {
		return;
	}

	$already_notified = (bool) get_post_meta( $request_id, '_wp_user_notified', true );

	if ( $already_notified ) {
		return;
	}

	// Localize message content for user; fallback to site default for visitors.
	if ( ! empty( $request->user_id ) ) {
		$locale = get_user_locale( $request->user_id );
	} else {
		$locale = get_locale();
	}

	$switched_locale = switch_to_locale( $locale );

	/**
	 * Filters the recipient of the data erasure fulfillment notification.
	 *
	 * @since 4.9.6
	 *
	 * @param string          $user_email The email address of the notification recipient.
	 * @param WP_User_Request $request    The request that is initiating the notification.
	 */
	$user_email = apply_filters( 'user_erasure_fulfillment_email_to', $request->email, $request );

	$email_data = array(
		'request'            => $request,
		'message_recipient'  => $user_email,
		'privacy_policy_url' => get_privacy_policy_url(),
		'sitename'           => wp_specialchars_decode( get_option( 'blogname' ), ENT_QUOTES ),
		'siteurl'            => home_url(),
	);

	$subject = sprintf(
		/* translators: Erasure request fulfilled notification email subject. %s: Site title. */
		__( '[%s] Erasure Request Fulfilled' ),
		$email_data['sitename']
	);

	/**
	 * Filters the subject of the email sent when an erasure request is completed.
	 *
	 * @since 4.9.8
	 *
	 * @param string $subject    The email subject.
	 * @param string $sitename   The name of the site.
	 * @param array  $email_data {
	 *     Data relating to the account action email.
	 *
	 *     @type WP_User_Request $request            User request object.
	 *     @type string          $message_recipient  The address that the email will be sent to. Defaults
	 *                                               to the value of `$request->email`, but can be changed
	 *                                               by the `user_erasure_fulfillment_email_to` filter.
	 *     @type string          $privacy_policy_url Privacy policy URL.
	 *     @type string          $sitename           The site name sending the mail.
	 *     @type string          $siteurl            The site URL sending the mail.
	 * }
	 */
	$subject = apply_filters( 'user_erasure_complete_email_subject', $subject, $email_data['sitename'], $email_data );

	if ( empty( $email_data['privacy_policy_url'] ) ) {
		/* translators: Do not translate SITENAME, SITEURL; those are placeholders. */
		$email_text = __(
			'Howdy,

Your request to erase your personal data on ###SITENAME### has been completed.

If you have any follow-up questions or concerns, please contact the site administrator.

Regards,
All at ###SITENAME###
###SITEURL###'
		);
	} else {
		/* translators: Do not translate SITENAME, SITEURL, PRIVACY_POLICY_URL; those are placeholders. */
		$email_text = __(
			'Howdy,

Your request to erase your personal data on ###SITENAME### has been completed.

If you have any follow-up questions or concerns, please contact the site administrator.

For more information, you can also read our privacy policy: ###PRIVACY_POLICY_URL###

Regards,
All at ###SITENAME###
###SITEURL###'
		);
	}

	/**
	 * Filters the body of the data erasure fulfillment notification.
	 *
	 * The email is sent to a user when a their data erasure request is fulfilled
	 * by an administrator.
	 *
	 * The following strings have a special meaning and will get replaced dynamically:
	 *
	 * ###SITENAME###           The name of the site.
	 * ###PRIVACY_POLICY_URL### Privacy policy page URL.
	 * ###SITEURL###            The URL to the site.
	 *
	 * @since 4.9.6
	 *
	 * @param string $email_text Text in the email.
	 * @param array  $email_data {
	 *     Data relating to the account action email.
	 *
	 *     @type WP_User_Request $request            User request object.
	 *     @type string          $message_recipient  The address that the email will be sent to. Defaults
	 *                                               to the value of `$request->email`, but can be changed
	 *                                               by the `user_erasure_fulfillment_email_to` filter.
	 *     @type string          $privacy_policy_url Privacy policy URL.
	 *     @type string          $sitename           The site name sending the mail.
	 *     @type string          $siteurl            The site URL sending the mail.
	 * }
	 */
	$content = apply_filters( 'user_confirmed_action_email_content', $email_text, $email_data );

	$content = str_replace( '###SITENAME###', $email_data['sitename'], $content );
	$content = str_replace( '###PRIVACY_POLICY_URL###', $email_data['privacy_policy_url'], $content );
	$content = str_replace( '###SITEURL###', esc_url_raw( $email_data['siteurl'] ), $content );

	$email_sent = wp_mail( $user_email, $subject, $content );

	if ( $switched_locale ) {
		restore_previous_locale();
	}

	if ( $email_sent ) {
		update_post_meta( $request_id, '_wp_user_notified', true );
	}
}