code: public function send_mail( $to, $subject = '', $message = '', $headers = array(), $attachments = array() ) {
  
  		if ( $this->options[ 'static_options' ][ 'mail_to_chunking' ][ 'chunking' ] === TRUE ) {
  			// the next group of recipients
  			$send_next_group = array();
  			if ( array_key_exists( 'send_next_group', $this->options[ 'static_options' ] ) ) {
  				$object_id       = $this->options[ 'static_options' ][ 'object' ][ 'id' ];
  				$send_next_group = $this->options[ 'static_options' ][ 'send_next_group' ][ $object_id ];
  			}
  
  			if ( $this->options[ 'send_by_bcc' ] ) {
  				$headers[ 'Bcc' ] = $this->get_mail_to_chunk( $headers[ 'Bcc' ], $send_next_group );
  			} else {
  				$to = $this->get_mail_to_chunk( $to, $send_next_group );
  			}
  		}
  
  		foreach ( $headers as $k => $v ) {
  			$headers[] = $k . ': ' . $v;
  			unset( $headers[ $k ] );
  		}
  
  		return wp_mail(
  			$to,
  			$subject,
  			$message,
  			$headers,
  			$attachments
  		);
  	}
docs: builds the header and sends mail
  
  @since 0.0.5 (2012.09.03)
  
  @param array $to
  @param string $subject
  @param string $message
  @param  array $headers
  @param  array $attachments
  
  @return  bool