function bbp_chunk_emails( $args = array() ) {

	// Get the maximum number of Bcc's per chunk
	$max_num = apply_filters( 'bbp_get_bcc_chunk_limit', 40, $args );

	// Look for "bcc: " in a case-insensitive way, and split into 2 sets
	$match       = '/^bcc: (\w+)/i';
	$old_headers = preg_grep( $match, $args['headers'], PREG_GREP_INVERT );
	$bcc_headers = preg_grep( $match, $args['headers'] );

	// Bail if less than $max_num recipients
	if ( empty( $bcc_headers ) || ( count( $bcc_headers ) < $max_num ) ) {
		return $args;
	}

	// Reindex the headers arrays
	$old_headers = array_values( $old_headers );
	$bcc_headers = array_values( $bcc_headers );

	// Break the Bcc emails into chunks
	foreach ( array_chunk( $bcc_headers, $max_num ) as $i => $chunk ) {

		// Skip the first chunk (it will get used in the original wp_mail() call)
		if ( 0 === $i ) {
			$first_chunk = $chunk;
			continue;
		}

		// Send out the chunk
		$chunk_headers = array_merge( $old_headers, $chunk );

		// Recursion alert, but should be OK!
		wp_mail(
			$args['to'],
			$args['subject'],
			$args['message'],
			$chunk_headers,
			$args['attachments']
		);
	}

	// Set headers to old headers + the $first_chunk of Bcc's
	$args['headers'] = array_merge( $old_headers, $first_chunk );

	// Return the reduced args, with the first chunk of Bcc's
	return $args;
}